Adds workflow for assigning DIY docs PR/issues openers to their creators (#57995)

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

.github/workflows/assign-diy-docs.yml

@@ -0,0 +1,30 @@
+name: Assign DIY docs issues
+
+on:
+  issues:
+    types: labeled
+  workflow_call:
+
+permissions:
+  contents: read
+jobs:
+  assign_diy_docs_issues:
+    name: Assign issues labelled with "DIY docs" to the issue creator
+    if: >-
+      github.repository_owner == 'github' && github.repository != 'github/docs' &&
+      github.event.label.name == 'DIY docs'
+    runs-on: ubuntu-latest
+    steps:
+      - name: Assign to creator
+        uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd
+        with:
+          script: |
+            const item = context.payload.issue;
+            const creator = item.user.login;
+            const issueNumber = item.number;
+            await github.rest.issues.addAssignees({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: issueNumber,
+              assignees: [creator]
+            });