Missing option to include license metadata

[techxplorer]

Describe the bug
I want to include a link to the license I use for my content on my site. I noticed that there is no option to do this.

I've also noticed an issue with the copyrightYear element in the ld+json metadata.

To Reproduce
License metadata - examine the metadata fields in the head tag and observe there is no license element

Copyright year - examine the copyright year element in ld+json schema. For pages it defaults to the current year, and for the homepage it defaults to the .Site.Params.Copyright value without replacing the placeholder for the current year.

Expected behavior
The ability to add license metadata and correct copyrightYear value in the ld+json schema.

[techxplorer]

I've lodged this issue and pull request. As this is my first time contributing, please let me know if there are any improvements that I can make in the future.