Add check-in template to issue templates list

[cesswairimu]

• PR is descriptively titled 📑 and links the original issue above 🔗
• tests pass -- look for a green checkbox ✔️ a few minutes after opening your PR -- or run tests locally with rake test
• code is in uniquely-named feature branch and has no merge conflicts 📁
• screenshots/GIFs are attached 📎 in case of UI updation
• ask @publiclab/reviewers for help, in a comment below

We're happy to help you get this ready -- don't be afraid to ask for help, and don't be discouraged if your tests fail at first!

If tests do fail, click on the red X to learn why by reading the logs.

Please be sure you've reviewed our contribution guidelines at https://publiclab.org/contributing-to-public-lab-software

Thanks!

[codecov]

Codecov Report

Merging #7949 into master will not change coverage.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master    #7949   +/-   ##
=======================================
  Coverage   82.04%   82.04%           
=======================================
  Files          97       97           
  Lines        5642     5642           
=======================================
  Hits         4629     4629           
  Misses       1013     1013           

Impacted Files	Coverage Δ
app/controllers/stats_controller.rb	73.33% <100.00%> (ø)

[jywarren]

Awesome!!!!!