WIP: CI: add spellcheck (#3421)

* CI: add spellcheck

* revert me

* CI: explicit command for spellchecker

* spellcheck: edit misspells

* CI: run spellcheck on diff

* spellcheck: edits

* spellcheck: edit misspells

* spellcheck: add rules

* spellcheck: mv configs

* spellcheck: more edits

* spellcheck: chore

* spellcheck: one more thing

* spellcheck: and another one

* spellcheck: seems like it doesn't get to an end

* spellcheck: new words after rebase

* spellcheck: new words appearing out of nowhere

* chore

* review edits

* more review edits

* more edits

* wonky behavior

* wonky behavior 2

* wonky behavior 3

* change git behavior

* spellcheck: another bunch of new edits

* spellcheck: new words are koming out of nowhere

* CI: finding the master

* CI: fetching master implicitly

* CI: undebug

* new errors

* a bunch of new edits

* and some more

* Update node/core/approval-voting/src/approval_db/v1/mod.rs

Co-authored-by: Andronik Ordian <write@reusable.software>

* Update xcm/xcm-executor/src/assets.rs

Co-authored-by: Andronik Ordian <write@reusable.software>

* Apply suggestions from code review

Co-authored-by: Andronik Ordian <write@reusable.software>

* Suggestions from the code review

* CI: scan only changed files

Co-authored-by: Andronik Ordian <write@reusable.software>

polkadot/runtime/common/src/lib.rs

@@ -121,7 +121,7 @@ pub type SlowAdjustingFeeUpdate<R> = TargetedFeeAdjustment<
 
 /// The type used for currency conversion.
 ///
-/// This must only be used as long as the balance type is u128.
+/// This must only be used as long as the balance type is `u128`.
 pub type CurrencyToVote = frame_support::traits::U128CurrencyToVote;
 static_assertions::assert_eq_size!(primitives::v1::Balance, u128);