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

Please review the following changes:
  * 00e1666 README.md: Add info about YaST module support & qualify few statements
  * 064b82d README.md: Link the "Module metadata" section better
  * 6840493 README.md: Improve workflow description in the "Overview" section
  * 4be874a README.md: Fix small errors
  * 263758e README.md: Add packages needed for testing to installation instructions
  * 39a489e README.md: Use backslashes to split a long command
  * 66ec073 README.md: Improve text in the "Update ycpc" section
  * 3aa1a3a README.md: Improve intro text