Support labeled issues

Now as soon as verify label is added into issue, appropriate action is executed

See readme for workflow file edit.

on:
  issues:
-  types: [opened]
+  types: [opened, labeled]
...
-      if: github.event.action == 'opened'
+      if: github.event.action == 'opened' || (github.event.action == 'labeled' && contains(github.event.issue.labels.*.name, 'verify'))