Draft: include blogposts in contribution guideline

I want to collect all the info about writing and formatting blog posts that are not documented properly yet

(yes, I am aware of the blog post about doing this, but they do not include workarounds for stuff like "the publication date comes from the file name, not the data field" or "how to include authors names"

view here

edit here

Memo to self: also write a blogpost as addition to the first "how to blog"