add example

RTL00_SDKV35a/component/common/example/httpd/readme.txt

@@ -0,0 +1,23 @@
+HTTPD EXAMPLE
+
+Description:
+Based on HTTPD API, an HTTP/HTTPS server example with a simple homepage and GET/POST method test pages are provided
+
+Configuration:
+[platform_opts.h]
+	#define CONFIG_EXAMPLE_HTTPD         1
+[lwipopts.h]
+	#define SO_REUSE                     1
+
+SSL Configuration for HTTPS:
+[config_rsa.h]
+	#define POLARSSL_CERTS_C
+	#define POLARSSL_SSL_SRV_C
+
+Execution:
+Can make automatical Wi-Fi connection when booting by using wlan fast connect example.
+A httpd example thread is started automatically when booting.
+Both HTTP and HTTPS are supported by this exmaple, and can be changed by modifying USE_HTTPS.
+Can test with a Web browser connecting to the homepage of httpd server.
+Should link PolarSSL bignum.c to SRAM to speed up SSL handshake if starting HTTPS server.
+