Update MegaMenu Application Customizer: Version bump to 1.1.0, localization support added, and unnecessary files removed

- Deleted obsolete localization file for English (en-us).
- Updated version number from 1.0.4 to 1.1.0 in manifests.js and manifests.json.
- Added localization support for German (de-de) in a new localization file.
- Removed unnecessary dependencies from manifests.
- Added .gitignore to exclude build artifacts and temporary files.

package.json

@@ -1,15 +1,16 @@
 {
   "name": "mega-menu",
-  "version": "1.0.4",
+  "version": "1.1.0",
   "private": true,
   "main": "lib/index.js",
   "engines": {
-    "node": ">=0.10.0"
+    "node": ">=6.9.0 <9.0.0"
   },
   "scripts": {
     "build": "gulp bundle",
     "clean": "gulp clean",
-    "test": "gulp test"
+    "test": "gulp test",
+    "package": "gulp clean && gulp bundle --ship && gulp package-solution --ship"
   },
   "dependencies": {
     "@microsoft/decorators": "~1.4.1",