Postmarks browser extension

A browser extension to send things to your Postmarks instance.

WIP. It sort of works.

• relies on existing Add Bookmark bookmarklet (no API for Postmarks as yet), opens as new tab, doesn't close cleanly on add.
• works in MS Edge, Chrome etc. (load unpacked extension)
• It looks like Firefox doesn't support background service workers / there is Manifest v3 stuff going on I haven't looked into properly. Probably needs a polyfill and/or a specific version.
• As yet unpackaged
• fragile

Related: Add to Postmarks Apple Shortcut