examples: create a new folder structure for generic network examples

simple_sniffer was moved from /wifi folder to /network folder

network_tests was moved from /system to /network folder

README's were updated accordingly to reflect new structure

examples/README.md

@@ -15,6 +15,7 @@ The examples are grouped into subdirectories by category. Each category director
 * `ethernet` Ethernet network examples.
 * `get-started` Simple examples with minimal functionality. Good start point for beginners.
 * `mesh` Wi-Fi Mesh examples.
+* `network` Examples related to general network environment, test & analysis.
 * `openthread` OpenThread examples.
 * `peripherals` Examples showing driver functionality for the various onboard ESP32 peripherals.
 * `protocols` Examples showing network protocol interactions.

examples/network/README.md

@@ -0,0 +1,5 @@
+# Network Examples
+
+Contains examples related to general network environment, test & analysis.
+
+See the [README.md](../README.md) file in the upper level [examples](../) directory for more information about examples.

examples/wifi/README.md

@@ -14,7 +14,6 @@ The examples are grouped into sub-directories by category. Each category directo
 * `power_save` contains a how to use power save mode of Wi-Fi.
 * `roaming` contains a example using 802.11k and 802.11v APIs.
 * `scan` shows how to scan for all the available APs.
-* `simple_sniffer` demonstrates basic usage of WiFi sniffer mode by saving packets into SD card with pcap format.
 * `smart_config` shows how ESP connects to a target AP with ESPTOUCH.
 * `wifi_easy_connect` shows how to configure an ESP device as an enrollee using Device Provisioning Protocol (DPP).
 * `wpa2_enterprise` connects to AP with WPA2 enterprise encryption.