Issue 4670 - Add a new build type for Gecko-based WebExtensions

templates/manifest.json.tmpl

 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 {
   "manifest_version": 2,
   {%- if releaseBuild %}
   "name": "__MSG_name__",
   {%- else %}
   "name": "__MSG_name_devbuild__",
@@ skipping 60 matching lines @@
   {%- endif %}
 
   {%- if backgroundScripts %}
   "background": {
     "scripts": {{backgroundScripts|json}},
     "persistent": true
   },
   {%- endif %}
 
   {%- if metadata.has_option('general', 'options') %}
+  {%- if type != 'edge' %}
+  "options_ui": {
+    "page": {{metadata.get('general', 'options')|json}},
+    "open_in_tab": true
+  },
+  {%- else %}
   "options_page": {{metadata.get('general', 'options')|json}},
+  {%- endif %}
   {%- endif %}
 
   {%- if metadata.has_option('general', 'devtools') %}
   "devtools_page": {{metadata.get('general', 'devtools')|json}},
   {%- endif %}
 
   {%- if contentScripts %}
   "content_scripts": {{contentScripts|json}},
   {%- endif %}
 
   {%- if webAccessible %}
   "web_accessible_resources": {{webAccessible|json}},
   {%- endif %}
 
   {%- if metadata.has_option('general', 'managedStorageSchema') %}
   "storage": {
     "managed_schema": {{metadata.get('general', 'managedStorageSchema')|json}}
   },
   {%- endif %}
 
   "_dummy": false
 }