Update readme
Update readme

Remove abbreviation.
Use "Addons.mozilla.org" instead of "AMO".
Mention the extension is avaiable on MS Edge Add-ons.

fakelbst/Chrome-Last.fm-Scrobbler,inverse/web-scrobbler,fakelbst/Chrome-Last.fm-Scrobbler,carpet-berlin/web-scrobbler,carpet-berlin/web-scrobbler,david-sabata/web-scrobbler,inverse/web-scrobbler,david-sabata/web-scrobbler