- Rename MainActivity to HomeActivity
- Move functions.kt one level up
- Rename package `extern` to `libraries`
- Fix layouts and layout elements (nomenclature:
`activity_fragment_element`)
- Move SectionsPagerAdapter code into the related activity kotlin file
In the actions / apps fragment of the launchers settings.
The terminology has to be improved and kept the same everywhere in the
app, as it also improves the codes readability and quality. I shall do
that soon.
