Add resources on publicity, social media, and photography

[elenam]

A web site, a twitter account, an article in a local newspaper and/or a sponsor's newsletter, etc.

MN events have a photographer. Nametags are marked with stickers: green for authorizing photos and their publication, yellow for "ask me first", and red for "no pictures".

I don't have time to do a write-up at the moment, but maybe someone who has this experience can (hint: MN group did a great job on this front!), or it will have to wait until I can.