fix(docs): prevent some symbols from being copied with (#20480)

docs/docs/contributing/local-backend.mdx

@@ -14,7 +14,7 @@ You also need to install MySQL or [MariaDB](https://mariadb.com/downloads).
 
 Ensure that you are using Python version 3.8 or 3.9, then proceed with:
 
-````bash
+```bash
 # Create a virtual environment and activate it (recommended)
 python3 -m venv venv # setup a python3 virtualenv
 source venv/bin/activate
@@ -47,18 +47,18 @@ Or you can install via our Makefile
 
 ```bash
 # Create a virtual environment and activate it (recommended)
-$ python3 -m venv venv # setup a python3 virtualenv
-$ source venv/bin/activate
+python3 -m venv venv # setup a python3 virtualenv
+source venv/bin/activate
 
 # install pip packages + pre-commit
-$ make install
+make install
 
 # Install superset pip packages and setup env only
-$ make superset
+make superset
 
 # Setup pre-commit only
-$ make pre-commit
-````
+make pre-commit
+```
 
 **Note: the FLASK_APP env var should not need to be set, as it's currently controlled
 via `.flaskenv`, however if needed, it should be set to `superset.app:create_app()`**
@@ -103,4 +103,5 @@ app.logger.info(form_data)
 ```
 
 ### Frontend Assets
+
 See [Building Frontend Assets Locally](https://github.com/apache/superset/blob/master/CONTRIBUTING.md#frontend)

docs/docs/installation/installing-superset-from-scratch.mdx

@@ -129,7 +129,7 @@ Finish installing by running through the following commands:
 
 ```
 # Create an admin user in your metadata database (use `admin` as username to be able to load the examples)
-$ export FLASK_APP=superset
+export FLASK_APP=superset
 superset fab create-admin
 
 # Load some data to play with

docs/docs/installation/installing-superset-using-docker-compose.mdx

@@ -44,7 +44,7 @@ all of the required dependencies. Docker Desktop [recently added support for Win
 following command:
 
 ```bash
-$ git clone https://github.com/apache/superset.git
+git clone https://github.com/apache/superset.git
 ```
 
 Once that command completes successfully, you should see a new `superset` folder in your
@@ -55,24 +55,24 @@ current directory.
 Navigate to the folder you created in step 1:
 
 ```bash
-$ cd superset
+cd superset
 ```
 
 When working on master branch, run the following commands:
 
 ```bash
-$ docker-compose -f docker-compose-non-dev.yml pull
-$ docker-compose -f docker-compose-non-dev.yml up
+docker-compose -f docker-compose-non-dev.yml pull
+docker-compose -f docker-compose-non-dev.yml up
 ```
 
 Alternatively, you can also run a specific version of Superset by first checking out
 the branch/tag, and then starting `docker-compose` with the `TAG` variable.
 For example, to run the 1.4.0 version, run the following commands:
 
 ```bash
-% git checkout 1.4.0
-$ TAG=1.4.0 docker-compose -f docker-compose-non-dev.yml pull
-$ TAG=1.4.0 docker-compose -f docker-compose-non-dev.yml up
+git checkout 1.4.0
+TAG=1.4.0 docker-compose -f docker-compose-non-dev.yml pull
+TAG=1.4.0 docker-compose -f docker-compose-non-dev.yml up
 ```
 
 You should see a wall of logging output from the containers being launched on your machine. Once