Add new contributors to DESCRIPTION file

[jgabry]

@utkarshpawade @ishaan-arora-1 You have both been very helpful with fixing issues with bayesplot recently. I would like to add you both as contributors in the package DESCRIPTION file to recognize your contributions. Two things:

1. Would you like to be included?
2. Can you check that I added your name correctly?

[utkarshpawade]

Yes, I'd love to be included and my name is correct, Thank you! :)

[ishaan-arora-1]

Yes @jgabry, would love that!! thankyou for the recognition

[jgabry]

Ok great, thank you both

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 99.18%. Comparing base (1061003) to head (32a53a7).
⚠️ Report is 2 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #545      +/-   ##
==========================================
- Coverage   99.21%   99.18%   -0.04%     
==========================================
  Files          35       35              
  Lines        6132     6132              
==========================================
- Hits         6084     6082       -2     
- Misses         48       50       +2     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.