Docs: Carousel documentation clarification

[Terran McCanna]

New bug created from previous omnibus bug: https://bugs.launchpad.net/evergreen/+bug/1851879

1) It would be helpful if the "Age Limit" field description gave examples of how ages should be entered (1 year, 6 months, 10 days, etc.)

2) In the section on the carousel types - in my experience, the "Newly Cataloged" carousel type requires shelving locations to work, but the "Newest Items by Shelving Location" carousel type does not. (This is the opposite of what it says in the documentation.)

3) It would also be helpful if the other carousel type descriptions indicated whether or not shelving locations are required.

[Gina Monti (gmonti90)]

I created a pull request and this needs a sign off/second look (only because I'm unsure if the corrections I created make any sense):

https://github.com/evergreen-library-system/Evergreen/pull/165

If there's a typo or anything, let me know, though I will read through and check again before committing.

[Gina Monti (gmonti90)]

The pull request is ready for review again. I edited a bit:

https://github.com/evergreen-library-system/Evergreen/pull/165

[Andrea Neiman (aneiman)]

Jane merged this for 3.8+ - marking Fix Committed for 3.8 and 3.9.