Docstring fixes for dev env values (#4747)

* Docstring change for add_dev_env_value

* Same for remove_dev_env_value

redbot/core/bot.py

@@ -287,7 +287,8 @@ class RedBase(
         Add a custom variable to the dev environment (``[p]debug``, ``[p]eval``, and ``[p]repl`` commands).
         If dev mode is disabled, nothing will happen.
 
-        .. admonition:: Example
+        Example
+        -------
 
         .. code-block:: python
 
@@ -312,8 +313,8 @@ class RedBase(
             The function returning the value of the variable.
             It must take a `commands.Context` as its sole parameter
 
-        Raise
-        -----
+        Raises
+        ------
         TypeError
             ``value`` argument isn't a callable.
         ValueError
@@ -357,8 +358,8 @@ class RedBase(
         name: str
             The name of the custom variable.
 
-        Raise
-        -----
+        Raises
+        ------
         KeyError
             The custom variable was never set.
         """