Update online game article

[ZynoXelek]

A small PR to update the ToC of the article with the main objective of making it shorter.

[ctmbl]

Nice pruning in my opinion 😉

While we're doing an update of this post maybe you could also add these:

• a link to the repo at the very beginning 🥲 this seems obvious but I think that for now there isn't any link except to the readme
• at every code block (or at least at main ones) a permalink to the code like that:

server.py:

def main():
    """Main function launching the parallel threads to manage the different aspects of the server.
    """
    global MAINSOCKET
    ...
    ```
    
    But these are just ideas!

[ctmbl]

also @ZynoXelek you should fetch new changes from the repo, rebase your branch and finally force push to this PR's branch. Because a lot of commits are listed here uselessly 😉

[ctmbl]

very nice update!
ready to merge 🚀