Trackpoint pinouts

Hi, thank you for the wiki! I found it very helpful while integrating a Trackpoint module into my keeb. I want to share feedback and suggest a few updates to make this work more useful for future readers. A lot of buy links are broken and lead to 404 today. Would be great to proof-check and prune them. In 2024, I found only two reliable sources to buy a Trackpoint module: * [Sprintek SK8707](https://github.com/joric/jorne/wiki/Trackpoint#sk8707). In the wiki, the link leads to "once upon a time" subreddit. It's mostly dead, but it leads to a lovely discord channel where you can meet smart trackpoint enthusiasts who will be happy to help. That being said, it is worth mentioning the discord channel (not the subreddit) but ultimately everything you need to know about this particular module can be boiled down to two resources: * Sprintek shop: https://www.sprintek.com/en/products/PointingStick.aspx * Datasheet. For instance, this one: https://cscott.net/DS0046%20SK8707%20Pointing%20Stick%20Module%20Datasheet.pdf (blame on Sprintek not publishing it) * [USB Trackpoints](https://github.com/joric/jorne/wiki/Trackpoint#usb-trackpoints) can be easily sourced from Amazon, Walmart, AliExpress and more. The problem is that it's relatively new product on the market and the pinout is not well documented online, however it's no longer a mystery. I've mapped it myself (see [here](https://imgur.com/a/03jCaPE)) and some people mentioned that this module has been documented in ZMK community (no proof). I hope I can contribute to the [Trackpoint page on deskthority](https://deskthority.net/wiki/TrackPoint_Hardware) after I get my account approved but I can't predict when it will happen. In the meantime, I believe the readers of this repo's wiki can benefit from learning the pinout without having to do additional research.