* docs: clean up SLES tab-sets
- Always use a tab-set for SLES 15.4
- In the toplevel SLES title don't say version 15
- harmonize the `:sync:` labels between documents
* docs: Misc fixes in installation
- Fix rocm repository url in the installer script installation for SLES
- Add a missing :sync: tab in installation prerequisites
* docs: add SLES 15.5 support to installation and OS support pages
* Remove install instructions for unsuported RHEL 8.8 and 9.2
Current ROCm release does not support these versions of RHEL
* Centralize disclaimers and perquisites for installation
- Move the single-version to multi-version diclaimer to the install
overview page where single vs multi installs are discussed.
- Move the installation of kernel-headers and development packages
to the install preparation page. Unify it mainly from the quick start
content.
* s/Name/name/ in repository config files for RHEL
The repository name can be set as `name=><name>` instead of `Name`,
otherwise yum complains about the repo not having a name, e.g:
```output
Repository 'ROCm-5.3.3' is missing name in configuration, using id.
```
This is fixed with this commit.
* Clean up render/video group section on prerequisites
* Installation and Upgrade restructuring & fixes
- Fix the rocm package urls for RHEL in the install & upgrade guides
- RHEL8 and 9 have different URLs, add a tab-set similar to ubuntu
for them.
- Fix the package URL in the upgrade guide for SLES (previously pointed
to the amdgpu url)
- Change the apt-signing key download and conversion to the method used
in the quick start guide, which is the recommended by ubuntu maintainers
- Change the install steps from list items to rubrics with numbered entries
which is more readable and matches the style in the quick start guide
- Do not pass `--append` to `tee` in the upgrade guide, because it is
meant to overwrite.
- Split the one long tab-set to multiple tab-sets in the upgrade guide
to improve readability
