Update CHANGELOG.md

Update Changelog for 2.16.1

Prepare for v2.16.0 release

Release v2.15.0

VAULT-8519 - Don't erroneously report nested JSON as unused keys (has…

…hicorp#559)

* Ignore section titles in unused keys

* Only ignore on HCL, not JSON

* VAULT-8519 Do not report nested JSON as unused keys

* VAULT-8519 Add extra test case

Co-authored-by: Scott G. Miller <[email protected]>

VAULT-8519 Add extra test case

Update CHANGELOG.md

Update CHANGELOG.md