[Rock-dev] Important note when creating rock-related github repositories

[Sylvain Joyeux]

Whenever you create a github repository for Rock, please include the
expressions "Rock" and "Robot Construction Kit" in the repository
*description*.

This is required so that they show up in a github search when looking
for either "Rock" "Rock Robot" and "Robot Construction Kit". Jan found
that out, and I started modifying the descriptions for the rock-core
repositories, which led to a much nicer search result (a.k.a. mostly
rock-core repositories showing up as first answers in the search).

Existing repositories still need to be modified (I just did around 5)

Sylvain