fix(docs): add instructions for including files in sidebar (#48624)

* Update how-to-work-on-the-docs-theme.md

* Update docs/how-to-work-on-the-docs-theme.md

Co-authored-by: Mrugesh Mohapatra <1884376+raisedadead@users.noreply.github.com>

docs/how-to-work-on-the-docs-theme.md

@@ -4,6 +4,8 @@
 
 To work on the contributing guidelines, you can edit or add files in the `docs` directory [available here](https://github.com/freeCodeCamp/freeCodeCamp/tree/main/docs). When your changes are merged, they will be made available automatically at the documentation site.
 
+When adding a new file to the `docs` directory, you should evaluate if the file should also be added to the sidebar navigation. We typically create a link in the [`_sidebar.md`](_sidebar.md) file for new and independent guides. Alternatively, You may follow the instructions below on creating an internal link for supporting guides.
+
 ### How to create an internal link
 
 If you want to create a link targeting a different section of the contributing guidelines, follow this format:
@@ -40,7 +42,7 @@ Typically you would not need to change any configuration or build the site local
 - We serve this file as a SPA using `docsify` and GitHub Pages.
 - The `docsify` script generates the content of `markdown` files in the `docs` directory on demand.
 - The homepage is generated from the [`_coverpage.md`](_coverpage.md).
-- the sidebar navigation is generated from [`_sidebar.md`](_sidebar.md).
+- The sidebar navigation is generated from [`_sidebar.md`](_sidebar.md).
 
 ### Serving the documentation site locally