Stop referencing V2 everywhere and move migration guide (#6737)

docs/framework_config.rst

@@ -446,49 +446,6 @@ Of course, if we're less than responsible pet owners, there are consequences::
                 "how poorly it was taken care of."
             )
 
-
-*************
-V2 Data Usage
-*************
-There has been much conversation on how to bring V2 data into V3 and, officially, we recommend that cog developers
-make use of the public interface in Config (using the categories as described in these docs) rather than simply
-copying and pasting your V2 data into V3. Using Config as recommended will result in a much better experience for
-you in the long run and will simplify cog creation and maintenance.
-
-However.
-
-We realize that many of our cog creators have expressed disinterest in writing converters for V2 to V3 style data.
-As a result we have opened up config to take standard V2 data and allow cog developers to manipulate it in V3 in
-much the same way they would in V2. The following examples will demonstrate how to accomplish this.
-
-.. warning::
-
-    By following this method to use V2 data in V3 you may be at risk of data corruption if your cog is used on a bot
-    with multiple shards. USE AT YOUR OWN RISK.
-
-.. code-block:: python
-
-    from redbot.core import Config, commands
-
-
-    class ExampleCog(commands.Cog):
-        def __init__(self):
-            self.config = Config.get_conf(self, 1234567890)
-            self.config.init_custom("V2", 1)
-            self.data = {}
-
-        async def load_data(self):
-            self.data = await self.config.custom("V2", "V2").all()
-
-        async def save_data(self):
-            await self.config.custom("V2", "V2").set(self.data)
-
-
-    async def setup(bot):
-        cog = ExampleCog()
-        await cog.load_data()
-        await bot.add_cog(cog)
-
 ************************************
 Best practices and performance notes
 ************************************