Use sphinx-prompt extension (#4908)

* Use sphinx-prompt extension

* Update PM2 guide

* Use an actual proper way to run Red with PM2

* Fix pm2 docs

Co-authored-by: Kowlin <Kowlin@users.noreply.github.com>

docs/update_red.rst

@@ -37,13 +37,14 @@ If you have Red 3.2.0 or newer, you can upgrade by following these 4 easy steps:
 
 2. Activate your venv with the following command:
 
-    .. code:: none
+    .. prompt:: batch
 
         "%userprofile%\redenv\Scripts\activate.bat"
 
 3. Update Red with this command:
 
-    .. code:: none
+    .. prompt:: batch
+        :prompts: (redenv) C:\\>
 
         python -m pip install -U Red-DiscordBot
 
@@ -64,19 +65,20 @@ If you have Red 3.2.0 or newer, you can upgrade by following these 4 easy steps:
   
     If you used ``venv`` for your virtual environment, use:
 
-    .. code:: none
+    .. prompt:: bash
 
         source ~/redenv/bin/activate
 
     If you used ``pyenv`` for your virtual environment, use:
 
-    .. code:: none
+    .. prompt:: bash
 
         pyenv shell <name>
 
 3. Update Red with this command:
 
-    .. code:: none
+    .. prompt:: bash
+        :prompts: (redenv) $
 
         python -m pip install -U Red-DiscordBot
 
@@ -107,7 +109,8 @@ Follow every step to ensure you have all dependencies up-to-date and only skip `
      - If you were using the MongoDB driver, **prior to launching your instance after update**,
        you will need to run the following commands to convert:
 
-         .. code::
+         .. prompt:: bash
+           :prompts: (redenv) $
 
            python -m pip install dnspython~=1.16.0 motor~=2.0.0 pymongo~=3.8.0
            redbot-setup convert [instancename] json
@@ -125,7 +128,8 @@ Red 3.0.2 and older
      - If you were using the MongoDB driver, **prior to updating**, you will need to convert your data to JSON backend,
        using following command:
 
-         .. code::
+         .. prompt:: bash
+           :prompts: (redenv) $
 
            redbot-setup --edit