[V3 Docs] Add docs on i18n (#1030)

docs/framework_i18n.rst

@@ -0,0 +1,54 @@
+.. i18n framework reference
+
+.. role:: python(code)
+    :language: python
+
+==============================
+Internationalization Framework
+==============================
+
+-----------
+Basic Usage
+-----------
+
+.. code-block:: python
+
+    from discord.ext import commands
+    from redbot.core.i18n import CogI18n
+    
+    _ = CogI18n("ExampleCog", __file__)
+
+    class ExampleCog:
+        """description"""
+
+        @commands.command()
+        async def mycom(self, ctx):
+            """command description"""
+            await ctx.send(_("This is a test command"))
+
+--------
+Tutorial
+--------
+
+After making your cog, generate a :code:`messages.pot` file
+
+The process of generating this will depend on the operating system
+you are using
+
+In a command prompt in your cog's package (where yourcog.py is),
+create a directory called "locales".
+Then do one of the following:
+
+Windows: :code:`python <your python install path>\Tools\i18n\pygettext.py -n -p locales`
+
+Mac: ?
+
+Linux: :code:`pygettext3 -n -p locales`
+
+This will generate a messages.pot file with strings to be translated
+
+-------------
+API Reference
+-------------
+
+.. automodule:: redbot.core.i18n