Introduced sample ini and repo files for easy development and run

1. Renamed katello_rapidnode.ini to katello_rapidnode.sample.ini
2. Renamed myrepofile.repo to myrepofile.sample.repo
3. Updated README to let the users know of copying and renaming the sample files
4. Updated gitignore to ignore the local config files
5. Updated README with Prerequisites
`katello-rapidnode` or `katello_rapidnode`?