[improve docs]: Template pallet (#1280)

* add and refactor docs

* commit mistake

* improvements

* fixes

* Apply suggestions from code review

Co-authored-by: Squirrel <[email protected]>

* fix: use markdown syntax

* from review: explain what generate_deposit does

* from review: add note about errors

* updates

* fix: bring back getter

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Co-authored-by: Squirrel <[email protected]>