Docs: Update Statistical Categories Editor section to reflect Angular interfaces

[Susan Morrison]

Creating this bug to assign to myself. In looking at new features for 3.11 and 3.12, I noticed the stat cat editor doc section needs updating to reflect the split-up Angular interfaces. I'll replace the Dojo screenshots and make the minor changes needed in the workflow instructions.

Current version:
https://docs.evergreen-ils.org/docs/latest/admin/lsa-statcat.html

[Susan Morrison (smorrison425)]

Added pull requests for
- text changes: https://github.com/spmorrison/Evergreen/pull/4
- updated screenshots: https://github.com/spmorrison/Evergreen/pull/5

[Andrea Neiman (aneiman)]

Picked to main and backported through rel_3_10.

Thank you, Susan!

[Susan Morrison (smorrison425)]

I'm sorry, Andrea, I realized I didn't use the correct folder in my image syntax. I'll fix those today or tomorrow and submit another pull request. Thank you for your help with this!

[Susan Morrison (smorrison425)]

Pull request for updated image syntax here: https://github.com/evergreen-library-system/Evergreen/pull/249

[Andrea Neiman (aneiman)]

No worries, sorry for not catching that! I will get this in later today.

[Andrea Neiman (aneiman)]

Picked to main & backported to 3.12. Thanks Susan!