Update Anonymous Column documents to reference ability to use strings

[lrljoe]

Docs Only update - add to the Anonymous Column docs

All Submissions:

• Have you followed the guidelines in our Contributing document?
• Have you checked to ensure there aren't other open Pull Requests for the same update/change?

New Feature Submissions:

1. Does your submission pass tests and did you add any new tests needed for your feature?
2. Did you update all templates (if applicable)?
3. Did you add the relevant documentation (if applicable)?
4. Did you test locally to make sure your feature works as intended?

Changes to Core Features:

• Have you added an explanation of what your changes do and why you'd like us to include them?
• Have you written new tests for your core changes, as applicable?
• Have you successfully ran tests with your changes locally?

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (69a64c3) 89.08% compared to head (2ca71ee) 89.08%.

Additional details and impacted files

@@            Coverage Diff             @@
##             develop    #1588   +/-   ##
==========================================
  Coverage      89.08%   89.08%           
  Complexity      1307     1307           
==========================================
  Files             99       99           
  Lines           3078     3078           
==========================================
  Hits            2742     2742           
  Misses           336      336           

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