Show HN: Shot-scraper video tool for recording YAML-defined webapp feature demos

Simon Willison is a well-known web developer and open-source creator (also co-founded Django). Shot-scraper is his existing CLI tool that takes screenshots of web pages and extracts data from them using YAML configuration files. This new video feature extends the same declarative YAML approach to recording short screencast-style videos of web applications. The key idea is that instead of manually recording feature demos (which are tedious to re-record when the UI changes), you define the demo as a config file — keystrokes, clicks, waits — and the tool plays it back against a live browser, producing a reproducible video. The "Show HN" in the title means it was posted to Hacker News as a project showcase. This matters because it makes software documentation more maintainable: when the UI changes, you update the YAML config and re-run the tool, instead of reshooting a video.