add firefox manifest to main

firefox/manifest.json

@@ -0,0 +1,42 @@
+{
+  "manifest_version": 2,
+  "name": "Linkwarden",
+  "description": "The browser extension for Linkwarden.",
+  "homepage_url": "https://linkwarden.app/",
+  "version": "1.0.4",
+  "browser_action": {
+    "default_popup": "./index.html",
+    "default_icon": {
+      "16": "./16.png",
+      "32": "./32.png",
+      "48": "./48.png",
+      "128": "./128.png"
+    },
+    "default_title": "Linkwarden"
+  },
+  "options_ui": {
+    "page": "./src/pages/Options/options.html",
+    "browser_style": false
+  },
+  "icons": {
+    "16": "./16.png",
+    "32": "./32.png",
+    "48": "./48.png",
+    "128": "./128.png"
+  },
+  "permissions": ["tabs", "http://*/*", "https://*/*"],
+  "commands": {
+    "_execute_action": {
+      "suggested_key": {
+        "default": "Alt+Shift+K",
+        "mac": "MacCtrl+Shift+K"
+      }
+    }
+  },
+  "browser_specific_settings": {
+    "gecko": {
+      "id": "[email protected]",
+      "strict_min_version": "109.0"
+    }
+  }
+}