#3302 Clarify behavior of Jekyll serve command regarding file changes.

Author: rjzupkoii

README.md

@@ -49,7 +49,7 @@ When you are initially working on your website, it is very useful to be able to
     ```
     then try run `bundle install` again. If succeeded, you should see a folder called `vendor` and `.bundle`.
 
-1. Run `jekyll serve -l -H localhost` to generate the HTML and serve it from `localhost:4000` the local server will automatically rebuild and refresh the pages on change.
+1. Run `jekyll serve -l -H localhost` to generate the HTML and serve it from `localhost:4000` the local server will automatically rebuild and refresh the pages on change to Markdown (*.md) and HTML files, while changes to the core template and configuration (i.e., `_config.yml`) will require stoping and restarting Jekyll.
     You may also try `bundle exec jekyll serve -l -H localhost` to ensure jekyll to use specific dependencies on your own local machine.
 
 If you are running on Linux it may be necessary to install some additional dependencies prior to being able to run locally: `sudo apt install build-essential gcc make`