First of all, thank for your contribution! I can't manage this whole thing alone, and I welcome pull requests. To make sure that we're all on the same page, here are some guidelines to follow for submitting pull requests for this list.
This is highly important - this list only contains freedom-respecting things! If you are sending a pull request linking to code, ensure it is licensed under a freedom-respecting license; if you are linking to assets of any kind, make sure that they are the same. For games, be especially careful that they are both.
Ensure that you use the correct name for the license (as per this or this), and indicate any further restrictions clearly. Also check if the license is in use already - if it is, don't create another link to it.
Pretty self-explanatory, really. Numbers are considered to be higher-ordered than anything else, and otherwise, lex order.
The commit message should state clearly what you did (adding, removing, clarifying, etc.), with what (usually by giving the name of the entry), in the present continuous tense (i.e. 'adding' not 'added').