Docs updates for OAuth overhaul

[infomiho]

• Migration docs from 0.12 to 0.13
• Updates to Google docs
• Updates to Github docs

[sodic]

Nice work!

I didn't run or check the code (I'm guessing you already covered that :).

My comments include suggestions you can implement or ignore. Merge when ready.

[sodic]

Suggested change

	The fields you receive will depend on the scopes you requested. The default scope is set to `profile` only. If you want to get the user's email, you need to specify the `email` scope in the `configFn` function.
	The fields you will receive depend on the scopes you requested. The default scope is set to `profile` only. If you want to get the user's email, you need to specify the `email` scope in the `configFn` function.

Maybe even without will, applies to other places too.

[sodic]

A common theme for the suggestions (I might have missed some along the same lines).

I suggest you use:

• "We" when you talk about the team (e.g., "we made some breaking changes...")
• "Wasp" when you talk about the framework (e.g., "Wasp gives you access to this field").

[sodic]

I like the before and after stuff, but it seems we lost the javascript/typescript split and this guide therefore only supports typescript?

No big deal, but just FYI to consider whether it makes sense in the future.

[infomiho]

I was deciding between having the complete matrix [ts, js] x [before, after] or not. It seemed cleaner to include only one of those: most people use Typescript and those using Javascript will get the idea of what needs to change.

[infomiho]

I'll merge this after we merge Github and Google changes.

[sodic]

Looks good, merge when ready!