docs: add contributor quick start guide for faster onboarding

CONTRIBUTING.quickstart.md

@@ -0,0 +1,294 @@
+# Cypress Contributor Quick Start Guide
+
+Welcome! This guide gets you coding on Cypress in under 15 minutes. Skip the overwhelming details and focus on the essentials to start contributing effectively.
+
+## 🚀 Quick Setup (5 minutes)
+
+### Prerequisites
+```bash
+# Check your Node.js version (required: ^20.1.0 || ^22.0.0 || >=24.0.0)
+node --version
+
+# If wrong version, use nvm
+nvm install 22.0.0
+nvm use 22.0.0
+```
+
+### Clone and Bootstrap
+```bash
+# Clone the repo
+git clone https://github.com/cypress-io/cypress.git
+cd cypress
+
+# Install dependencies (this takes a few minutes)
+yarn install
+
+# Verify everything works
+yarn workspace @packages/driver test:unit:ci --run
+```
+
+**✅ Success indicator**: You should see tests passing without errors.
+
+## 🎯 High-Impact Areas (Pick Your Battle)
+
+### 1. 🐛 Quick Bug Fixes
+**Where**: `packages/driver/src/` - Core test execution logic
+**Why**: Direct user impact, well-defined problems
+**Start here**: Issues labeled `good first issue` + `driver`
+
+### 2. 🔧 CLI Improvements  
+**Where**: `cli/lib/` - Command-line interface
+**Why**: Affects every Cypress user, easier to test locally
+**Start here**: Issues labeled `cli` + `enhancement`
+
+### 3. 📚 Component Testing
+**Where**: `npm/react/`, `npm/vue/`, `npm/vite-dev-server/`
+**Why**: Growing area, lots of room for improvement
+**Start here**: Issues labeled `component testing`
+
+### 4. 🧪 Test Infrastructure
+**Where**: `system-tests/`, `packages/*/test/`
+**Why**: Improve DX for all contributors
+**Start here**: Flaky test issues, missing test coverage
+
+## 💻 Essential Development Workflows
+
+### Run Specific Package Tests
+```bash
+# Driver (core test execution)
+yarn workspace @packages/driver test:unit
+
+# CLI (command-line interface)  
+cd cli && yarn test
+
+# Server (backend logic)
+yarn workspace @packages/server test:unit
+
+# Component testing (React example)
+yarn workspace @cypress/react test
+```
+
+### Build and Test Locally
+```bash
+# Build everything (rarely needed)
+yarn build
+
+# Build specific package
+yarn workspace @packages/driver build
+
+# Run system tests (integration tests)
+yarn test:ci:system-tests:chrome:specs
+```
+
+### Debug Like a Pro
+```bash
+# Enable debug output
+export DEBUG="cypress:*"
+
+# Run Cypress with your changes
+yarn cypress:open
+
+# Or test specific functionality
+yarn workspace @packages/driver cy:open
+```
+
+## 🛠️ Project Structure (Just the Essentials)
+
+```
+cypress/
+├── packages/           # Core packages
+│   ├── driver/        # Test execution engine ⭐
+│   ├── server/        # Backend API ⭐  
+│   ├── app/          # Desktop app UI
+│   └── ...
+├── cli/              # Command-line interface ⭐
+├── npm/              # Framework integrations ⭐
+│   ├── react/        # React component testing
+│   ├── vue/          # Vue component testing
+│   └── vite-dev-server/ # Vite integration
+├── system-tests/     # End-to-end tests ⭐
+└── guides/          # Development docs
+```
+
+**⭐ = High contribution activity**
+
+## 🔥 Common Commands (Copy-Paste Ready)
+
+### Daily Development
+```bash
+# Start developing
+git checkout develop && git pull origin develop
+git checkout -b feature/my-awesome-change
+
+# Run tests while coding
+yarn workspace @packages/driver test:unit --watch
+
+# Check your changes work end-to-end
+yarn cypress:open
+
+# Before committing
+yarn lint
+```
+
+### Debugging Failing Tests
+```bash
+# Run specific test file
+yarn workspace @packages/driver test:unit cypress/integration/commands/actions/click_spec.js
+
+# Run with browser debugging
+yarn workspace @packages/driver test:debug
+
+# Run system test for specific feature  
+yarn test:ci:system-tests:chrome --spec "cypress/e2e/commands/actions.cy.js"
+```
+
+### PR Preparation
+```bash
+# Lint and fix common issues
+yarn lint --fix
+
+# Run affected tests
+yarn test:ci:affected --base=develop
+
+# Build and verify
+yarn build && yarn cypress:verify
+```
+
+## 🎬 Your First Contribution (15-minute walkthrough)
+
+### Step 1: Find an Issue (2 min)
+1. Go to [Cypress Issues](https://github.com/cypress-io/cypress/issues)
+2. Filter: `label:"good first issue"` + `label:"help wanted"`
+3. Pick something tagged `driver`, `cli`, or `component testing`
+4. Comment: "I'd like to work on this"
+
+### Step 2: Set Up Branch (1 min)
+```bash
+git checkout develop
+git pull origin develop  
+git checkout -b fix/issue-XXXXX-description
+```
+
+### Step 3: Make Your Change (10 min)
+Focus on the minimal change that fixes the issue:
+- **Driver**: Usually in `packages/driver/src/`
+- **CLI**: Usually in `cli/lib/` 
+- **Component Testing**: Usually in `npm/{framework}/`
+
+### Step 4: Test It (2 min)
+```bash
+# Run relevant tests
+yarn workspace @packages/driver test:unit --grep "your test description"
+
+# Test manually if needed
+yarn cypress:open
+```
+
+## 🚨 Common Gotchas (Save Yourself Time)
+
+### "Tests pass locally but fail in CI"
+- **Cause**: Missing `await` or race conditions
+- **Fix**: Add proper async/await, check system-tests
+
+### "Yarn install fails"
+- **Cause**: Node version mismatch or cache issues
+- **Fix**: `nvm use 22 && yarn cache clean && yarn install`
+
+### "Cannot find module @packages/xyz"  
+- **Cause**: Workspace linking issues
+- **Fix**: `yarn install` from project root (not inside packages)
+
+### "Changes don't seem to take effect"
+- **Cause**: Need to rebuild package
+- **Fix**: `yarn workspace @packages/driver build`
+
+## 🔍 Finding Your Way Around
+
+### Key Files to Know
+```bash
+# Where commands are implemented  
+packages/driver/src/cy/commands/
+
+# Where assertions live
+packages/driver/src/cy/assertions.ts
+
+# CLI command definitions
+cli/lib/commands/
+
+# Error messages and codes
+cli/lib/errors.ts
+packages/driver/src/cypress/error_messages.js
+
+# Integration test examples
+system-tests/projects/
+```
+
+### Who to Ask
+- **Driver/Core**: `@cypress/driver-team`
+- **CLI**: `@cypress/cli-team`  
+- **Component Testing**: `@cypress/component-team`
+- **General**: `#contributors` in [Discord](https://discord.gg/cypress)
+
+## 🎯 Pro Tips
+
+### 1. Start Small
+- Fix typos, improve error messages, add tests
+- Build confidence before tackling complex features
+
+### 2. Read Related Tests
+- Tests are often better documentation than docs
+- Look at `*.spec.js` files in the same directory
+
+### 3. Use the Debugger
+```javascript
+// In driver code
+cy.then(() => {
+  debugger; // Pause execution in DevTools
+})
+```
+
+### 4. Check Existing Solutions
+```bash
+# Search codebase for similar implementations
+git grep -r "similar functionality"
+
+# Check if there's a utility function
+git grep -r "function.*helper"
+```
+
+## 📈 Level Up Your Contributions
+
+### After Your First PR
+1. **Ask for more challenging issues** - Mention your successful PR
+2. **Review other PRs** - Great way to learn the codebase
+3. **Improve documentation** - Always needed, high impact
+4. **Fix flaky tests** - Huge value to the team
+
+### Become a Power Contributor
+- **Own an area**: Become the go-to person for React component testing, CLI, etc.
+- **Write RFCs**: Propose new features in `guides/`
+- **Mentor others**: Help new contributors in Discord
+
+## 📚 What's Next?
+
+### Essential Reading (in order)
+1. This guide (you're here!)
+2. [CONTRIBUTING.md](../CONTRIBUTING.md) - Full contributor guide
+3. [guides/testing-strategy-and-styleguide.md](../guides/testing-strategy-and-styleguide.md)
+4. Package-specific READMEs in your area of interest
+
+### Advanced Topics
+- [guides/typescript.md](../guides/typescript.md) - TypeScript patterns
+- [guides/testing-other-projects.md](../guides/testing-other-projects.md) - Testing strategy
+- [guides/release-process.md](../guides/release-process.md) - How releases work
+
+---
+
+**🎉 Ready to contribute?** Pick an issue and dive in! The Cypress community is here to help.
+
+**❓ Questions?** 
+- [Discord #contributors](https://discord.gg/cypress)
+- [GitHub Discussions](https://github.com/cypress-io/cypress/discussions)
+- Comment on your chosen issue
+
+**Remember**: Every expert was once a beginner. Your fresh perspective is valuable!