Resolve "Wrap APIDocsExample cURL URLs in quotes."

Summary & how to test

This MR resolves a minor issue in our API documentation.

If you use bash, you won't run into issues running our curl examples. However, if you use zsh (and possibly other $SHELLs), examples containing URLs with query strings won't work properly, as & forces the command into the background.

How to test:

In both bash and zsh, execute:

curl -X GET -H "Authorization: Token YOUR_TOKEN" http://localhost:8000/api/database/rows/table/TABLE_ID/?user_field_names=true

It'll fail in zsh:

zsh: no matches found: http://localhost:8000/api/database/rows/table/TABLE_ID/?user_field_names=true

Then try it again with the URL in double quotes:

curl -X GET -H "Authorization: Token YOUR_TOKEN" "http://localhost:8000/api/database/rows/table/TABLE_ID/?user_field_names=true"

Merge Request Checklist

• changelog.md has been updated if required
• New/updated Premium features are separated correctly in the premium folder
• The latest Chrome and Firefox have been used to test any new frontend features
• Documentation has been updated
• Quality Standards are met
• Performance: tables are still fast with 100k+ rows, 100+ field tables
• The redoc API pages have been updated for any REST API changes
• Our custom API docs are updated for changes to endpoints accessed via api tokens
• The UI/UX has been updated following UI Style Guide

Closes #1462 (closed)