Added theme without keyboard

[WR4F]

Solves the problem behind issue #259

There is now a theme named tron-notype that has no keyboard and also has a larger filesystem pane. Change it to your default theme by editing userData/settings.json and changing "theme":"tron" to "theme":"tron-notype".

[Escalion]

It would be nicer if the _renderer.js function to initialise the UI could be passed an option so that the keyboard isn't rendered into the DOM at all.

It would be a serious rewrite and would require layout arguments to be defined in a configuration file so that the user can fully define each component available on the display.

[GitSquared]

@Escalion the overrall architecture of eDEX was made with the possibility of customising components in mind. However this feature won't be implemented soon because

1. there aren't any "extra" components to choose from yet

2. i need to fully rewrite components and their architecture to make separate threads for rendering and collecting information

Also right now the keyboard, the filesystem display and the terminal are deeply linked to each other and don't follow the same principles as other modules like the clock or the globe. I might consider the possibility of customising them one day, but that's even further away.

In the meantime this PR is a good workaround and keeping the keyboard working even though it's invisible shouldn't harm the CPU too much. Merging.