Interactive maps messages review

This pull request was created only for message review purposes. Do not merge it!

Dear ComEng developers: pick red or green background to review the messages and their documentation, please :)

Once you finish review and we address all found issues we'll be able to delete the branch.
I think in the context of the page, it seems ok. This is just the header, the longer explanation text is below (wikia-interactive-maps-no-maps-text).