[mv3] Add missing file related to previous commit

Related commit:
- https://github.com/gorhill/uBlock/commit/872eafa37858

platform/mv3/scriptlets/css-generichigh.template.css

@@ -0,0 +1,26 @@
+/*******************************************************************************
+
+    uBlock Origin - a browser extension to block requests.
+    Copyright (C) 2014-present Raymond Hill
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see {http://www.gnu.org/licenses/}.
+
+    Home: https://github.com/gorhill/uBlock
+*/
+
+/* $rulesetId$ */
+
+$selectorList$ {
+    display: none !important;
+}