Release 3.2.1

• Update documentation links to use gh-pages, and add action to publish gh-pages from Yard docs.
• Update dependencies for rack-linkeddata >= 3.2.3 and sinatra ~> 3.0.

Release 3.2.0

• Minimum Ruby version now 2.6.

Release 3.1.3

Use rack-linkeddata 3.1.3.

Release 3.1.2

Use rack-linkeddata 3.1.2.

Release 3.1.1

Version 3.1.1

Depends on rack-linkeddata 3.1.1.

Release 3.1.0

• Update for 3.1 release and Ruby 2.7 calling sequences.