Adds "Release Notes/Known Bugs" to Changelog,updates file format to markdown, standardizes the format of previous entries

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.As it will display on the Forge, updates file type to markdown and standardizes previous entries. Adds template for release notes to be filled in later.
Merge pull request #165 from laurenrother/1.0.x

Add "Release Notes/Known Bugs" to Changelog
Prepare for supported modules.
Merge pull request #164 from apenney/add-metadata

Prepare for supported modules.
Prepare supported module 1.0.2.
Merge pull request #167 from apenney/supported-101

Prepare supported module 1.0.2.
Add in missing files to work around Puppet bug.
Merge pull request #168 from apenney/last-minute-metadata-fix

Add in missing files to work around Puppet bug.