readm3 0.11.0: a plain text editor, on the web and the Linux desktop

readm3.com/viewer is now a plain, fast text editor in the spirit of Sublime Text, minus the plugins.

• CodeMirror editor: line numbers, syntax colors for ~100 languages (loaded on demand, cached offline), multiple cursors (Ctrl+click, Ctrl+D, Alt+drag), find and replace, folding, bracket matching, Ctrl+/ comments.
• Real files: Open folder / Open files work on the files themselves in Chrome, Edge, the installed app and the desktop app. Ctrl+S saves back to disk, Ctrl+Shift+S is Save As, ● marks a file whose disk copy is behind.
• Ctrl+P quick open, Ctrl+Shift+P / F1 command palette, tabs.
• The installed PWA appears in your system's "Open with" for text files.

Desktop app (Linux x64), attached below once the Desktop workflow finishes:

• readm3-linux-x86_64.flatpak: flatpak install --user readm3-linux-x86_64.flatpak (keeps Chromium's sandbox; prefer it on Ubuntu 24.04+)
• readm3-linux-x86_64.AppImage: chmod +x and run, or curl -fsSL https://readm3.com/install.sh | sh -s -- --desktop
• SHA256SUMS

readm3-desktop notes.md src/app.ts opens files as tabs; Ctrl+S writes them back.

Full details: #26