Add missed dict-extra contributors

[DanielJenkins]

Some contributors to the open source packages in the Elm community were left off.

I have added the missing individuals who contributed to https://github.com/elm-community/dict-extra as of writing on Mar 13, 2024 (Feb 16, 2022 was the date of the last merged PR).

Here is the list of all contributors to that package: https://github.com/elm-community/dict-extra/graphs/contributors
Full disclosure: This includes myself (elm-community/dict-extra#22)

A note for possible follow-up: There may be others who contributed to other packages who were also missed.

[gampleman]

Thanks and my apologies for the omission. I used an automated script to extract the contributors, but there are so many that it's hard to sanity check.

[DanielJenkins]

@gampleman no hard feelings! Thank you for the quick turnaround!