document the backports policy
Created by: fkr
Instead of the contributor guide, the Release-Policy document was chosen, since there other (similar) items are being defined. The backports policy was discussed in Team 3 meeting on April 14th as part of the OVN exporter backport discussion:
https://github.com/SovereignCloudStack/issues/issues/22
Addresses: #60 (closed)
Signed-off-by: Felix Kronlage-Dammers fkr@hazardous.org