Design a suite of new lead images for the Blog

Hi @nicob, we talked about this a while ago, but I wanted to drop a ticket, so we can get organized. I'm thinking that we should update some of our "stock" hero images for the blog to match the categories we have. The goal is to have some default visuals that we can refer to when we are talking about a topic more generally, i.e. anti-censorship or network health, without any specific tool/product/announcement attached to it.

Some top level ideas:

• Maybe we can pull from the new icon set?
• We could align more with the new web design?
• We could think of something completely independent and new?

Only thing that I would like to make sure is to cover the existing blog categories: https://gitlab.torproject.org/tpo/tpa/team/-/wikis/service/blog#list-of-categories

Let's have a short kick-off here to determine what could make sense and what's realistic in terms of timeline. 😄