Fix broken API documentation links
Summary
Development:
- Please rename "RTEMS CPU Kit Doxygen" to "RTEMS API documentation" linked from https://docs.rtems.org/
- Please fix the link https://docs.rtems.org/doxygen/branches/master/ so that it reads "main" instead of "master"
- Please update the API documentation to 5.3 because it is only for "RTEMS 5.0.0" on the main branch
Release 5.3
- Please rename "RTEMS CPU Kit Doxygen" to "RTEMS API documentation" linked from https://docs.rtems.org/
- Please fix the link to the API documentation on 5.3 because the link is currently broken https://docs.rtems.org/doxygen/releases/rtems-5.3/ with error 404
The API docs links for 5.2, 5.1 and 4.11 are not broken, so something terrible happened recently