General developer forum

In that particular case I'm thinking of making the heading there be the same as the name of the news forum itself (obvious really) so that all you'll need to do in 1.0.8 is edit the forum itself.

But, to answer your question, you should create a copy of a whole existing language directory (ie en or en_us) to your own new "language" (eg en_tb) which you set as the default site language (and the admin user's language), then edit away happily using the web interface.