[Review] Request from '' @ 'yast/ycp-killer/last-minute-readme-fixes-try-2'

Please review the following changes:
  * 58c3d77 README.md: Add info about YaST module support & qualify few statements
  * 8189287 README.md: Link the "Module metadata" section better
  * 152f0e0 README.md: Improve workflow description in the "Overview" section
  * f38fe65 README.md: Fix small errors
  * ffb9b1b README.md: Add packages needed for testing to installation instructions
  * 2398461 README.md: Use backslashes to split a long command
  * 79b9b4e README.md: Improve text in the "Update ycpc" section
  * 43c3dc0 README.md: Improve intro text