DOC: Fix typos "Scientific" to "scientific"

[yvonnefroehlich]

Description of proposed changes

Just minor typo fixes following
#3447 (comment).

Fixes #

Preview:

Reminders

• Run make format and make check to make sure the code follows the style guide.
• Add tests for new features or tests that would have caught the bug that you're fixing.
• Add new public functions/methods/classes to doc/api/index.rst.
• Write detailed docstrings for all functions/methods.
• If wrapping a new module, open a 'Wrap new GMT module' issue and submit reasonably-sized PRs.
• If adding new functionality, add an example to docstrings or tutorials.
• Use underscores (not hyphens) in names of Python files and directories.

Slash Commands

You can write slash commands (/command) in the first line of a comment to perform
specific operations. Supported slash command is:

• /format: automatically format and lint the code

[seisman]

@yvonnefroehlich Please also fix the following files:

README.md
194:rest of the Scientific Python ecosystem, and therefore:

doc/maintenance.md
127:rest of the Scientific Python ecosystem, and therefore:

[yvonnefroehlich]

@yvonnefroehlich Please also fix the following files:

README.md
194:rest of the Scientific Python ecosystem, and therefore:

doc/maintenance.md
127:rest of the Scientific Python ecosystem, and therefore:

Done in the commits ded80ed and
19653a0.