Add /generate_labels function + fix issues

pr_agent/settings/pr_description_prompts.toml

@@ -19,11 +19,22 @@ PR Title:
   description: an informative title for the PR, describing its main theme
 PR Type:
   type: array
+{%- if enable_custom_labels %}
   description: One or more labels that describe the PR type. Don't output the description in the parentheses.
+{%- endif %}
   items:
     type: string
     enum:
+{%- if enable_custom_labels %}
 {{ custom_labels }}
+{%- else %}
+      - Bug fix
+      - Tests
+      - Refactoring
+      - Enhancement
+      - Documentation
+      - Other
+{%- endif %}
 PR Description:
   type: string
   description: an informative and concise description of the PR.
@@ -47,7 +58,11 @@ Example output:
 PR Title: |-
   ...
 PR Type:
+{%- if enable_custom_labels %}
+{{ custom_labels_examples }}
+{%- else %}
   - Bug fix
+{%- endif %}
 PR Description: |-
   ...
 PR Main Files Walkthrough: