Update the module's Acknowledgments section

[thetuvix]

The AR module and hit-test module have both just inherited their Acknowledgments section from the core spec. We should be explicit and update it to list the folks who contributed to the module themselves.

Come to think of it, the core spec's Acknowledgments section is itself stale - there are plenty of folks we should thank that are not present there.

[cwilso]

We should update these, and tend to be more inclusive in them (aka "I'd rather thank people who didn't do much than not thank someone who did.")