update License page

[ritikarawlani]

Update license page to clarify which license applies where.

• "creative commons apply in general except for software"
• "All the CQL and its derivatives used with SMART Guidelines in this IG is to be licensed to BSD"
• Javascript is part of publishing tooling, it's not content, its not relevant
• Cucumber/Gherkin @litlfred please add
• FML @litlfred please add

recommending : fhir.org/guides/cqf/common/license.html

CQF uses apache license 2.0

WHO to run through LEG to confirm.