Allow IP ranges where start_address equals end_address to model
single-IP pools like DHCP or NAT reservations. Add validation tests,
filterset coverage, and display logic to render both endpoints.
Fixes#21993
* Incorporate local documentation build in upgrade script
* Add docs build to CI
* Include docs build path in revision control
* Update footer dcos link
* Changelog for #6328
* Clean up errant links