Flash code via a web browser

[jakeg]

I've made (partly by copying code from @kaluma/cli ) a way to flash the Pico directly from a web browser, using the web serial API.

Try it at https://www.mathsuniverse.com/pico

I created this partly because I'm using WSL on Windows, and connecting to the Pico via WSL is a bit of a faff (having to share the USB port etc).

It's very rough-and-ready but features:

• Button to connect to Pico
• Auto-connects to previous connected Picos
• Shows Kaluma's terminal
• Open a file from your computer
• If you edit that file elsewhere, it reloads it
• Flash that file to the Pico
• It's all just a single HTML file, under 400 lines with JS/CSS inlined

Enjoy and let me know of any bugs etc!