Add function mapWithKey

[flip111]

Can mapWithKey be added for the times that you want to keep all items (opposed to mapMaybeWithKey)?

[natefaubion]

See the FunctorWithIndex instance

purescript-ordered-collections/src/Data/Map/Internal.purs

Line 150 in 313ec0c

instance functorWithIndexMap :: FunctorWithIndex k (Map k) where

[flip111]

Thanks @natefaubion

Can a hint be added to documentation here?

purescript-ordered-collections/src/Data/Map/Internal.purs

Lines 651 to 652 in db50eee

	-- | Applies a function to each key/value pair in a map, discarding entries
	-- | where the function returns `Nothing`.