Add settings menu

[forgottosave]

Description

A small settings menu would be nice to have. This settings menu could be inserted directly into the Lichess menu (example on the right).

Implementation would require:

• create settings tab
• inserting the settings button into html (possible javascript insertion with webview.loadUrl("javascript:...") and javascript-code below)

  var element = document.getElementById("topnav");
  var lwaSection = '<section><a href="/analysis">Lichess Web App</a><div role="group"><a href="settings:">Settings</a><a href="https://github.com/forgottosave/LichessWebApp/issues">Report Bug</a></div></section>'
  var githubSection = '<section><a href="/analysis">Github</a><div role="group"><a href="https://github.com/lichess-org">Lichess</a><a href="https://github.com/forgottosave/LichessWebApp">Lichess Web App</a></div></section>'
  element.insertAdjacentHTML( 'beforeend', lwaSection );
  element.insertAdjacentHTML( 'beforeend', githubSection );
  

• connect the button with the settings tab

Alternatives

There are two alternative options:

1. One could argue, that settings aren't that necessary and maybe not needed for such a simple app.
2. The Menu Button could be added elsewhere as a sort of overlay and not directly into the html