Writes the delimiters for an empty attribute description

[michaeltlombardi]

Describe the Bug

If a Puppet Resource API type attribute has an empty description of '' or "" then that is literally what will be placed in the output instead of nil/an empty line.

Expected Behavior

A type attribute with an empty string for a description writes an empty line under its header and type.

Steps to Reproduce

1. Change the descriptor of any attribute in a Puppet Resource API Type to an empty string.
2. pdk bundle exec puppet strings generate --format markdown --out REFERENCE.md