[Review] Request from '' @ 'yast/ycp-killer/readme-improvements'

Please review the following changes:
  * 1ebc262 README.md: Add the "Overview" section
  * 189fd98 README.md: Move & rename the "Resulting Directory Structure" section
  * 78c0e0f README.md: Improve step 2 in the installation a bit
  * 3a2a630 README.md: Simplify the introduction