Adding sig-security-assessments Slack Channel!

See above - I'm attempting to update this file to enable the creation of a new slack channel for self-assessments!

Author: aladewberry

communication/slack-config/sig-security/config.yaml

@@ -3,4 +3,4 @@ channels:
   - name: sig-security-assess-capi
   - name: sig-security-docs
   - name: sig-security-tooling
-
+  - name: sig-security-assessments