Add GSoC 2025 results blog post

[Kobzol]

This blog post describes the results of our GSoC 2025 projects, similar to last year's post. I'm opening it as a draft early to gather feedback from GSoC mentors and contributors.

GSoC 2025 is ending on November 17; I plan to publish this post on November 18.

• For mentors: please check that the project summaries of your project(s) look OK to you. I rewrote your text slightly to fit it into the writing style of the whole post, and also had to shorten it in a few places to avoid the blog post becoming even larger than it already is.
• For contributors: please check that the project summary makes sense, and that the name that we used for you is OK. In some places, I just used the GitHub handle, but we can use your full name if you want. Please let me know which name you would prefer!

Note that the blog post is generated from a bunch of MarkDown files with a Python script. So if you don't like something about e.g. the layout of the post, let me know, I can change that quite easily across all projects.

Rendered

[Kobzol]

I plan to publish the blog post tomorrow, on November 18.

[Kobzol]

Thanks everyone for providing feedback!