[Chapel Merge] Add LICENSE file

Branch: refs/heads/main
Revision: 2e74eb0
Author: bradcray
Log Message:

Merge pull request #3 from bradcray/add-license

Add LICENSE file

I just copied the highlight.js LICENSE since BSD 3-clause is fairly
innocuous and this isn’t a repo likely to have anything we’re
particularly protective of.

Modified Files:
A LICENSE

Compare: https://github.com/chapel-lang/highlightjs-chapel/compare/608c94140662...2e74eb08ba56