* Added "Shift+Alt+M" as a shortcut to open and close sidebar

- Adds a contextual menu to reload pinafore.

* I've switched to a new Mastodon web client called pinafore by Nolan Lawson, it has the following advantages over the previous approach:
- Has multiple account support
- Will work with all instances
- Is very lightweight

Pinafore is available as a standalone PWA Mastodon client at https://pinafore.social

The old approach was using an iframe to open the official mastodon UI from your chosen instance. This had problems as many instances use CSP which prevents iframing. By using a new PWA client as a sidebar we have all the advantages of a real client on a very nimble package.