docs(websocket): add pytest dependencies and execution instructions

Author: surengab

components/esp_websocket_client/examples/target/README.md

@@ -15,6 +15,27 @@ This example can be executed on any ESP32 board, the only required interface is
 * Configure the websocket endpoint URI under "Example Configuration", if "WEBSOCKET_URI_FROM_STDIN" is selected then the example application will connect to the URI it reads from stdin (used for testing)
 * To test a WebSocket client example over TLS, please enable one of the following configurations: `CONFIG_WS_OVER_TLS_MUTUAL_AUTH` or `CONFIG_WS_OVER_TLS_SERVER_AUTH`. See the sections below for more details.
 
+### Pre-configured SDK Configurations
+
+This example includes several pre-configured `sdkconfig.ci.*` files for different testing scenarios:
+
+* **sdkconfig.ci** - Default configuration with WebSocket over Ethernet (IP101 PHY, ESP32, IPv6) and hardcoded URI.
+* **sdkconfig.ci.plain_tcp** - WebSocket over plain TCP (no TLS, URI from stdin) using Ethernet (IP101 PHY, ESP32, IPv6).
+* **sdkconfig.ci.mutual_auth** - WebSocket with mutual TLS authentication (client/server certificate verification, skips CN check) and URI from stdin.
+* **sdkconfig.ci.dynamic_buffer** - WebSocket with dynamic buffer allocation, Ethernet (IP101 PHY, ESP32, IPv6), and hardcoded URI.
+
+To use a specific configuration for building:
+```
+rm sdkconfig
+cp sdkconfig.ci.plain_tcp sdkconfig
+idf.py build
+```
+
+Or specify it directly when building:
+```
+idf.py -DSDKCONFIG_DEFAULTS="sdkconfig.ci.plain_tcp" build
+```
+
 ### Server Certificate Verification
 
 * Mutual Authentication: When `CONFIG_WS_OVER_TLS_MUTUAL_AUTH=y` is enabled, it's essential to provide valid certificates for both the server and client.
@@ -73,7 +94,36 @@ idf.py -p PORT flash monitor
 
 (To exit the serial monitor, type ``Ctrl-]``.)
 
-See the Getting Started Guide for full steps to configure and use ESP-IDF to build projects.
+See the [ESP-IDF Getting Started Guide](https://docs.espressif.com/projects/esp-idf/en/latest/esp32/get-started/index.html) for full steps to configure and use ESP-IDF to build projects.
+
+## Testing with pytest
+
+### Install Dependencies
+
+Before running the pytest tests, you need to install the required Python packages:
+
+```
+pip install -r esp-protocols/ci/requirements.txt
+```
+
+### Run pytest
+
+After installing the dependencies, you can run the pytest tests:
+
+Run all tests in current directory:
+```
+pytest .
+```
+
+Run specific test file:
+```
+pytest pytest_websocket.py
+```
+
+To specify the target device or serial port, use:
+```
+pytest --target esp32 --port /dev/ttyUSB0
+```
 
 ## Example Output