New category to generate topic specific rss feeds

@jck @jandecaluwe @josyb

I am going to make a new category, gsoc-update (or something) so that I can create an RSS feed to PSF. Let me know if there are any objections (too many categories) of preferred category formats (GSoC-Updates).

Can we have sub-categories?

It looks like discourse support two-levels (one subcategory). That is a better idea! I might have to play with it some to see if the RSS feed can be generated.