fix(create-docusaurus): Improve init template README, fix headings and remove $ in bash code blocks (#11157)

packages/create-docusaurus/templates/shared/README.md

@@ -2,40 +2,40 @@
 
 This website is built using [Docusaurus](https://docusaurus.io/), a modern static website generator.
 
-### Installation
+## Installation
 
 ```bash
-$ yarn
+yarn
 ```
 
-### Local Development
+## Local Development
 
 ```bash
-$ yarn start
+yarn start
 ```
 
 This command starts a local development server and opens up a browser window. Most changes are reflected live without having to restart the server.
 
-### Build
+## Build
 
 ```bash
-$ yarn build
+yarn build
 ```
 
 This command generates static content into the `build` directory and can be served using any static contents hosting service.
 
-### Deployment
+## Deployment
 
 Using SSH:
 
 ```bash
-$ USE_SSH=true yarn deploy
+USE_SSH=true yarn deploy
 ```
 
 Not using SSH:
 
 ```bash
-$ GIT_USER=<Your GitHub username> yarn deploy
+GIT_USER=<Your GitHub username> yarn deploy
 ```
 
 If you are using GitHub pages for hosting, this command is a convenient way to build the website and push to the `gh-pages` branch.