Fix some spelling mistakes in "Resources" help info.

In the "More" text for the Resource Editor, a couple typoes:

1) "You can upload two types of resources..." Actually, there are three resource types listed there.

2) "messages_[COUTNRY].properties", should be "COUNTRY", of course

and that's it.

rday

P.S. While I'm here, I might as well be picky about grammar:

• "used in other places of Studio", "of" should be "in", as it is in the opening line

• " translate Nuxeo UI text messages in other languages", should read "into other languages"