Add links, more licenses, save-to-file, and markdown-compatible output

[mayel]

With my apologies for not having much time to clean this up, but hope it's useful to others.

[coveralls]

Pull Request Test Coverage Report for Build 56

• 32 of 37 (86.49%) changed or added relevant lines in 4 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage increased (+1.007%) to 65.734%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
lib/licensir/scanner.ex	5	7	71.43%
lib/mix/tasks/licenses.ex	18	21	85.71%

Files with Coverage Reduction	New Missed Lines	%
lib/csv/encoding/encode.ex	1	75.0%

Totals
Change from base Build 54:	1.007%
Covered Lines:	188
Relevant Lines:	286

---

💛 - Coveralls