Add "Release Notes/Known Bugs" to Changelog

Per a request to have initial release notes that specifically listed known issues for this PE 3.2 release, and barred by time constraints from automating a pull from open issues in JIRA, this commit adds a Release Note and Known Bug section to the Changelog for the imminent 3.2 release.
Merge branch 'changelog' of github.com:laurenrother/puppetlabs-registry into changelog

Conflicts:
Fixes formatting