feat: add .pre-commit-config.yaml for vala-lint

Integrate vala-lint to automate code style checks.
See: https://github.com/vala-lang/vala-lint

Author: kuyacarlo

.pre-commit-config.yaml

@@ -0,0 +1,9 @@
+repos:
+  - repo: local
+    hooks:
+      - id: vala-lint
+        name: Vala-Lint
+        entry: env LD_LIBRARY_PATH=/usr/local/lib64 GIO_USE_VFS=local dbus-run-session -- io.elementary.vala-lint
+        language: system
+        files: \.(vala|gs)$
+