Replace all instances of "6to5" with "Babel"

[UltCombo]

The posts seem dated/unmaintained when they read "6to5", as 6to5 has been rebranded to Babel a while ago.
I believe we should keep the posts up to date and use the current name, and also check whether there are any outdated usage snippets and fix them.
WDYT? @jaydson

[jaydson]

That's a good idea.