Update Documentation Emphasizing the Need to have Transition Permission to Close Issues

Recently, we have had a few users(mainly those updating from JIRA 5.X to 6.X) complaining that they cannot close issues.

We requested that they run permission helper to ensure they had all necessary permissions which always showed they did.

When we requested that they send us their permission scheme, we realized they did not have permission to transition issues and deducing that since when you close an issue the issue has to change state from the current state it was in to closed state, we tested this and confirmed that they needed this permission.

We would appreciate if relationships between permissions are emphasized in the documentation so customers are aware of them.