docs: add GM plugin EN doc to make website display normally (#8393)

* docs: add GM plugin EN doc to make website display normally

* Delete main text only keep the opening remarks and Chinese link

* update Doc Lints details

docs/en/latest/config.json

@@ -102,7 +102,8 @@
             "plugins/referer-restriction",
             "plugins/consumer-restriction",
             "plugins/csrf",
-            "plugins/public-api"
+            "plugins/public-api",
+            "plugins/gm"
           ]
         },
         {

docs/en/latest/plugins/gm.md

@@ -0,0 +1,31 @@
+---
+title: GM
+keywords:
+  - APISIX
+  - Plugin
+  - GM
+description: This article introduces the basic information and usage of the Apache APISIX `gm` plugin.
+---
+
+<!--
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+-->
+
+:::info
+The function usage scenarios introduced in this article are mainly in China, so this article only has a Chinese version temporarily. You can cilik [here](https://apisix.apache.org/zh/docs/apisix/plugins/gm/) for more details. If you are interested in this feature, welcome to translate this document.
+:::