ci: add go-docs file and copyright scripts

Signed-off-by: Xinwei Xiong(cubxxw-openim) <3293172751nss@gmail.com>

scripts/gendoc.sh

@@ -0,0 +1,37 @@
+#!/usr/bin/env bash
+# Copyright © 2023 OpenIM. All rights reserved.
+#
+# Licensed 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.
+
+# Iterates over two directories: 'pkg' and 'internal/pkg'.
+for top in pkg internal/pkg tools
+do
+    # Finds all subdirectories (including nested ones) under the current directory in the iteration ('pkg' or 'internal/pkg').
+    for d in $(find $top -type d)
+    do
+        # Checks if 'doc.go' doesn't exist in the current subdirectory.
+        if [ ! -f $d/doc.go ]; then
+            # Checks if there are any '.go' files in the current subdirectory.
+            if ls $d/*.go > /dev/null 2>&1; then
+                # Echoes the path of the 'doc.go' file to the terminal. 
+                # This is likely for debugging or information purposes.
+                echo $d/doc.go
+
+                # Writes the package declaration and import comment to the 'doc.go' file in the current subdirectory.
+                # 'basename $d' retrieves the name of the current directory (last part of the path).
+                # The import comment is constructed based on a static base URL and the directory path.
+                echo "package $(basename $d) // import \"github.com/OpenIMSDK/Open-IM-Server/$d\"" > $d/doc.go
+            fi
+        fi
+    done
+done