Update CHANGELOG and docs #2861

   * Add test for license ambiguity
   * Remove previous license clarity scoring plugin

Signed-off-by: Jono Yang <jyang@nexb.com>

Author: JonoYang

CHANGELOG.rst

@@ -170,7 +170,6 @@ scancode_post_scan =
     summary-key-files = summarycode.summarizer:ScanKeyFilesSummary
     summary-by-facet = summarycode.summarizer:ScanByFacetSummary
     license-clarity-score = summarycode.score:LicenseClarityScore
-    license-clarity-score-2 = summarycode.score2:LicenseClarityScore2
     license-policy = licensedcode.plugin_license_policy:LicensePolicy
     mark-source = scancode.plugin_mark_source:MarkSource
     classify-package = summarycode.classify:PackageTopAndKeyFilesTagger