Stop using abbreviated names of attributes in UI.
Merge pull request #225 from Gaelan/just_call_it_perception

Stop using abbreviated names of attributes in UI.
fix(typo): percepition to perception

Fixes https://github.com/HabitRPG/habitrpg/issues/3586
feat(backgrounds): add backgrounds feature
feat(backgrounds): group bgs into sets in content.coffee, for easier
"purchase set"
feat(backgrounds): i18n for backgrounds
chore(i18n): update locales
i18n(background): Backgrounds => "User Backgrounds" @lemoness
chore(i18n): update locales
fix(backgrounds): clearer wording wrt lim editions

Fixes https://github.com/HabitRPG/habitrpg/issues/3610
feat(dilatory): WIP