Change link for "Help translate STEP..." to go to new Help page on the subject

[DavidIB]

The link for "Help translate STEP..." is at the top of the Language interface picker box.
Currently it goes straight to Crowdin.com, which is confusing for most people.
We now have a Help page about this, with its own link to Crowdin.
So, change the link to http://crowdin.net/project/step
to a link to: https://stepbibleguide.blogspot.com/p/stepbible-interface-language.html