Add codespell

Signed-off-by: Adam Warner <me@adamwarner.co.uk>

.github/workflows/codespell.yml

@@ -0,0 +1,18 @@
+name: Codespell
+on:
+  pull_request:
+    types: [opened, synchronize, reopened, ready_for_review]
+
+jobs:
+  spell-check:
+    if: github.event.pull_request.draft == false
+    runs-on: ubuntu-latest
+    steps:
+    -
+      name: Checkout repository
+      uses: actions/checkout@v3
+    -
+      name: Spell-Checking
+      uses: codespell-project/actions-codespell@master
+      with:
+        ignore_words_file: .codespellignore