CI: Add a codespell action

Author: kostis

.github/workflows/codespell.yml

@@ -0,0 +1,11 @@
+name: codespell
+on: [push, pull_request]
+jobs:
+  codespell:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v6
+    - uses: codespell-project/actions-codespell@master
+      with:
+        path: src
+        ignore_words_list: ElseF