docs: update the documents based on customer feedbacks

docs/en/api-reference/protocols/icmp_echo.rst

@@ -65,7 +65,12 @@ Example method to create a new ping session and register callbacks:
     void initialize_ping()
     {
         /* convert URL to IP address */
-        getaddrinfo("www.espressif.com", NULL, &hint, &res) == 0);
+        ip_addr_t target_addr;
+        struct addrinfo hint;
+        struct addrinfo *res = NULL;
+        memset(&hint, 0, sizeof(hint));
+        memset(&target_addr, 0, sizeof(target_addr));
+        getaddrinfo("www.espressif.com", NULL, &hint, &res);
         struct in_addr addr4 = ((struct sockaddr_in *) (res->ai_addr))->sin_addr;
         inet_addr_to_ip4addr(ip_2_ip4(&target_addr), &addr4);
         freeaddrinfo(res);

docs/en/get-started/windows-setup.rst

@@ -30,7 +30,7 @@ https://dl.espressif.com/dl/esp-idf-tools-setup-2.3.exe
 
 The installer includes the cross-compilers, OpenOCD, CMake_ and Ninja_ build tool. The installer can also download and run installers for Python_ 3.7 and `Git For Windows`_ if they are not already installed on the computer.
 
-The installer also offers to download one of the ESP-IDF release versions. Please choose a directory for downloading ESP-IDF. The recommended directory is ``%userprofile%\esp`` where ``%userprofile%`` is your home directory. If you do not have it yet, please run the following command to create a new one:
+The installer also downloads one of the ESP-IDF release versions, or offers to use an existing one, if already present on your PC. If you don't have one, please choose a directory for downloading ESP-IDF. The recommended directory is ``%userprofile%\esp`` where ``%userprofile%`` is your home directory. If you do not have it yet, please run the following command to create a new one:
 
 .. code-block:: batch
 

docs/zh_CN/get-started/windows-setup.rst

@@ -26,7 +26,11 @@ ESP-IDF 工具安装器
 
 https://dl.espressif.com/dl/esp-idf-tools-setup-2.3.exe
 
-本安装器可为您安装所需的交叉编译器、OpenOCD、cmake_ 和 Ninja_ 编译工具，以及一款 mconf-idf_ 配置工具。此外，本安装器还可在有需要时下载、运行 Python_ 3.7 和 `Git For Windows` 的安装器。
+.. 重要：下次更新此链接时，请重新写文件 get-started/index.rst 中“其它文件下载方式”这一章节，然后将此条注意事项删除。
+
+本安装器可为您安装所需的交叉编译器、OpenOCD、CMake_ 和 Ninja_ 编译工具。此外，本安装器还可在有需要时下载、运行 Python_ 3.7 和 `Git For Windows`_ 的安装器。
+
+您可以使用之前已经下载的 ESP-IDF 版本，如果没有的话，本安装器还可用于下载任意 ESP-IDF 发布版本。推荐将 ESP-IDF 下载到 ``%userprofile%\esp`` 目录下，其中 ``%userprofile%`` 代表家目录。可运行以下命令，创建 ``%userprofile%\esp``。
 
 本安装器还可用于下载任意 ESP-IDF 发布版本。