feat(v2): Improve the initial templates #4302 (#4320)

* feat: add getting started doc at classic inital templates

* fix: improve the contents of getting started page

* fix: fix slug routing

* fix: rename gettingStarted to getting-started and re-adjust the content

* feat: add markdown-features docs

* feat: add a page on how to create a simple document

* feat: add a page on how to create pages

* feat: add create a post doc

* feat: add thank you page with whats next

* feat : update sidebar.js

* feat : add introduction content

* feat : add self hosting content

* feat : add GitHub pages content

* fix : remove automatically deploying with github actions content

* feat : add deploying to netlify

* feat : add Translate your site

* add : Manage versions

* fix : formatted docs with prettier

* Revert "fix : formatted docs with prettier"

This reverts commit af8c0b48

* run prettier to init templates with fixes

* complete new init template

* rename manage-docs-versions

* change wording

* refresh config file

* rework init template homepage

* minor changes

Co-authored-by: Lisa Chandra <52909743+lisa761@users.noreply.github.com>
Co-authored-by: Javid <singularity.javid@gmail.com>
Co-authored-by: ShinteiMai <stevenhanselgo@gmail.com>
Co-authored-by: slorber <lorber.sebastien@gmail.com>

packages/docusaurus-init/templates/classic/docs/create-a-page.md

@@ -2,7 +2,7 @@
 title: Create a Page
 ---
 
-Any React or Markdown file created under `src/pages` directory is converted into a website page:
+Add **Markdown or React** files to `src/pages` to create **standalone pages**:
 
 - `src/pages/index.js` -> `localhost:3000/`
 - `src/pages/foo.md` -> `localhost:3000/foo`