Add link to testing instance of Gitea

dotfiles/config/bmo/wish.ini

     wnoise  = https://mynoise.net/NoiseMachines/whiteNoiseGenerator.php
     rdt     = https://www.reddit.com/subreddits/
     so      = https://stackoverflow.com/
+    tgi     = https://try.gitea.io/
     tjc     = https://together.jolla.com/
     tor     = https://theoldreader.com/
     tw      = https://twitter.com/