Restore RawGit page

[MartinKolarik]

In #400 we somehow lost the RawGit page. Needs to be restored, migrated to the new design (similar to https://www.jsdelivr.com/github) and added to the top menu and footer.

[jimaek]

But all rawgit urls redirect to jsDelivr anyway, what would be the point of the page?

[MartinKolarik]

I forgot about the redirects and don't think we discussed the page removal. Still, RawGit points to that missing page now. I think we should keep it to at least explain what happened, similarly like we still have https://jsdelivr.com/osscdn. Changing to lower priority though.

[jimaek]

How about we just make a new page called migrated services and we list everything instead of making new pages every time.

[MartinKolarik]

@jimaek let's have the page designed then.