chore: set up commitlint, husky, and prettier (#1451)

* chore: add prettier configuration

Signed-off-by: Xe Iaso <me@xeiaso.net>

* format: run prettier tree-wide

Signed-off-by: Xe Iaso <me@xeiaso.net>

* chore(prettier): ignore intentionally ungrammatical files

Signed-off-by: Xe Iaso <me@xeiaso.net>

* ci: add PR title lint rule

Signed-off-by: Xe Iaso <me@xeiaso.net>

* ci: add DCO check

Signed-off-by: Xe Iaso <me@xeiaso.net>

* chore: add commitlint and husky

Signed-off-by: Xe Iaso <me@xeiaso.net>

* chore: add CONTRIBUTING guidelines

Signed-off-by: Xe Iaso <me@xeiaso.net>

* chore: set SKIP_INTEGRATION in precommit tests

Signed-off-by: Xe Iaso <me@xeiaso.net>

* chore: update spelling

Signed-off-by: Xe Iaso <me@xeiaso.net>

* ci(dco): remove reopened trigger

Signed-off-by: Xe Iaso <me@xeiaso.net>

* chore: remove dead file

Signed-off-by: Xe Iaso <me@xeiaso.net>

* chore(prettier): don't format nginx includes

Signed-off-by: Xe Iaso <me@xeiaso.net>

---------

Signed-off-by: Xe Iaso <me@xeiaso.net>

.github/workflows/lint-pr-title.yaml

@@ -0,0 +1,19 @@
+name: "Lint PR"
+
+on:
+  pull_request_target:
+    types:
+      - opened
+      - edited
+      - synchronize
+
+jobs:
+  lint_pr_title:
+    name: Validate PR title
+    runs-on: ubuntu-latest
+    permissions:
+      pull-requests: read
+    steps:
+      - uses: amannn/action-semantic-pull-request@0723387faaf9b38adef4775cd42cfd5155ed6017 # v5.5.3
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}