Improve modularity

[Maingron]

Define: Extensions = Combination of HTML Template and JS which together make up a block, for example.

Currently you can write Extensions like this: Block Templates in HTML and JS separately.

In future there should be a new parser which allows to write everything / every extension respectively in it's own clockHTML file.

The parser would then import all Extensions.
Maybe something like this:

mymod.html:

<template something>
... (HTML Templates goes here)

<tick>
developers_custom_function() {
  document.body.style.opacity -= .1;
}
</tick>
</template>

Where <tick> would be the JavaScript which currently would have to be hardcoded into the js tick section.

With the new system, <tick> would be eliminated from the cached extension file by the parser and instead be appended to the cached global tick.

Those "cached" files are rebuilt every time the clock is reloaded and should probably be stored in CachedStorage(). Once they're built, they'd get appended to the index.html, I guess.

This is a major change, but it'd be a good change.