Add a line to the to index page make it clearer that well-represented groups are welcome.
Add a line to the to index page make it clearer that well-represented groups are welcome.

Based on @joewreschnig's suggestion on issue #91: https://github.com/computeranonymous/computer/issues/91#issuecomment-25435140
patrickod/computer,tdfischer/computer,SaraDGore/computer,ComputerAnonymousSeattle/computer,patrickod/computer,tdfischer/computer,ComputerAnonymousSeattle/computer