docs: Improve example for composing outputs (#206)

Author: yafanasiev

.github/workflows/lint-pr-title-preview-outputErrorMessage

@@ -23,7 +23,7 @@ jobs:
       - uses: marocchino/sticky-pull-request-comment@v2
         # When the previous steps fails, the workflow would stop. By adding this
         # condition you can continue the execution with the populated error message.
-        if: always()
+        if: always() && (steps.lint_pr_title.outputs.error_message != null)
         with:
           header: pr-title-lint-error
           message: |

README.md

@@ -145,7 +145,7 @@ jobs:
       - uses: marocchino/sticky-pull-request-comment@v2
         # When the previous steps fails, the workflow would stop. By adding this
         # condition you can continue the execution with the populated error message.
-        if: always()
+        if: always() && (steps.lint_pr_title.outputs.error_message != null)
         with:
           header: pr-title-lint-error
           message: |