chore(.github): PR시 작성자가 Assignees이 되는 action 추가 (#41)

.github/assign.yml

@@ -0,0 +1,2 @@
+# Set addAssignees to 'author' to set the PR creator as the assignee.
+addAssignees: author

.github/workflows/assign.yml

@@ -0,0 +1,13 @@
+name: Assign
+on:
+  pull_request_target:
+    types: [opened, ready_for_review]
+
+jobs:
+  add-assignees:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: kentaro-m/[email protected]
+        with:
+          configuration-path: '.github/assign.yml' # Only needed if you use something other than .github/auto_assign.yml