[Team page] Add Caleb, Deet, and Thomas to Acknowledgements section

[garyhtou]

@cjdenio, @Deetschoe, and @SerenityUX have helped shape Hack Club into what it is today! Let's add/move them to the acknowledgments section of the team page.

### Tasks
- [ ] Add @cjdenio
- [ ] Add @Deetschoe 
- [ ] Add @SerenityUX 

[taciturnaxolotl]

I can do this!

[taciturnaxolotl]

Can we get a merge on this? i want to get some cookies and chai!