Tidy & polish Norway meetup notes

[teodorlu]

Two documents were written preparing for the Oslo Clojure meetup in December 2025:

• https://clojurecivitas.org/clojure_norway/meetup_2025_12.html — short example of tablecloth and tableplot.
• https://clojurecivitas.org/clojure_norway/meetup_2025_12/violin.html — longer example analyzing the sounds a violin makes.

Both are currently in draft status on Civitas. I'd like to tidy and polish them out of draft status.

Context: We recently made a website to keep track of past Oslo Clojure meetups, topics and references. These two documents would be a great way to remember what we actually did! The meetup site is at https://osloclojuremeetup.github.io/.

cc @daslu. If you wish, we could just use this PR for tidying both of the Norway Meetup documents.

[daslu]

@teodorlu That is great.

I suggest the following:

• add an :image (so it will appear nicely at the Civitas website) -- like here: https://github.com/ClojureCivitas/clojurecivitas.github.io/blob/main/src/dtype_next/image_processing_with_tensors.clj
• modify the :date to the day at which you merge the PR, e.g., 2026-12-06 -- this way the post will appear at the top of the list of posts and will be noticeable.
• add an opening paragraph that explains this was originally given at a Clojure/Oslo meetup (and add a link).
• if you wish, maybe add links to things like Tableplot, which are not so well known.

Sounds ok?

[teodorlu]

Agreed on all points!

I posted as draft because the PR isn't done! I just wanted to get it out into the open to:

1. Avoid us doing the same things
2. and (if you want) make a branch where we can do both our work!