Add bug label to documentation issue template (#7090)

Author: bhoradc

.github/ISSUE_TEMPLATE/documentation.yml

@@ -2,7 +2,7 @@
 name: "📕 Documentation Issue"
 description: Report an issue in the API Reference documentation or Developer Guide
 title: "(short issue description)"
-labels: [documentation, needs-triage]
+labels: [documentation, needs-triage, bug]
 assignees: []
 body:
   - type: textarea