feat: update application icons and add marketing assets

- Replaced the application icon in package.json with a larger version for better visibility.
- Added a new logo image file `logo_larger.png` to the public directory.
- Introduced a Dockerfile for the marketing section to serve static files using Nginx.
- Created a new `index.html` file for the marketing site, featuring a responsive layout and sections for features and technology stack.

app/package.json

@@ -107,7 +107,7 @@
           ]
         }
       ],
-      "icon": "public/logo.png"
+      "icon": "public/logo_larger.png"
     },
     "win": {
       "target": [
@@ -118,7 +118,7 @@
           ]
         }
       ],
-      "icon": "public/logo.png"
+      "icon": "public/logo_larger.png"
     },
     "linux": {
       "target": [
@@ -136,7 +136,7 @@
         }
       ],
       "category": "Development",
-      "icon": "public/logo.png",
+      "icon": "public/logo_larger.png",
       "maintainer": "webdevcody@gmail.com"
     },
     "nsis": {