Allow players to disable entering full-screen on application launch

[jelster]

Is your feature request related to a problem? Please describe.
When the game is launched from the HTML home page, it automatically enters full screen mode. This isn't a problem, but it's a PITA during development because it requires exiting full screen mode, potentially while managing debugging breakpoints.

Describe the solution you'd like
A checkbox on the HTML page defaults to "checked". Label can describe that it toggles the setting, which maybe sets a URL query string indicating the user's preference.

Additional context
when settings are more fleshed out and local storage is made available to the app, this is an ideal place to move user-specific preferences