Update Rocky Linux 8.7 Build Instructions and Replace .tsh with .sh

[beatreichenbach]

Linked issues

Related discussions

https://github.com/AcademySoftwareFoundation/OpenRV/discussions/346 https://github.com/AcademySoftwareFoundation/OpenRV/discussions/352 https://github.com/AcademySoftwareFoundation/OpenRV/discussions/90 https://github.com/AcademySoftwareFoundation/OpenRV/discussions/382

Summarize your change.

Adding documentation for Rocky Linux 8.7 Build.

Describe the reason for the change.

The existing documentation was lacking.

Describe what you have tested and on which operating system.

Rocky Linux 8.7

Add a list of changes, and note any that might need special attention during the review.

If possible, provide screenshots.