feat(scripts): add intro in dependabot config

Author: Illia Obukhau

.github/dependabot.yml

@@ -1,3 +1,6 @@
+# This file was generated by `generate-dependabot-config.mjs` script.
+# To update config, run `pnpm update-dependabot-config` in automation/scripts package.
+# WARNING: All changes made to this file will be overwritten.
 version: 2
 updates:
   - package-ecosystem: github-actions

automation/scripts/generate-dependabot-config.mjs

@@ -44,7 +44,14 @@ function main() {
         ]
     };
 
-    writeFileSync(path.resolve(root, ".github/dependabot.yml"), yaml.stringify(dependabotConfig), {
+    const intro = [
+        "# This file was generated by `generate-dependabot-config.mjs` script.",
+        "# To update config, run `pnpm update-dependabot-config` in automation/scripts package.",
+        "# WARNING: All changes made to this file will be overwritten."
+    ];
+    const content = [...intro, yaml.stringify(dependabotConfig)].join("\n");
+
+    writeFileSync(path.resolve(root, ".github/dependabot.yml"), content, {
         encoding: "utf-8"
     });
 }