AMBARI-24466. Add README.md for Ambari project (#2390)
AMBARI-24466. Add README.md for Ambari project (#2390)

* AMBARI-24466 Add README.md for Ambari project

* AMBARI-24466. Add sub-project + fix rat issue

* AMBARI-24466. Add jenkins build badge.

* AMBARI-24466. Us trunk commit build status instead of PR one for jenkins build badge.

sekikn/ambari,sekikn/ambari,sekikn/ambari,sekikn/ambari,sekikn/ambari,sekikn/ambari,sekikn/ambari,sekikn/ambari,sekikn/ambari