pyserial driver: add pipe command on cli

packages/jumpstarter-driver-pyserial/README.md

@@ -33,6 +33,58 @@ export:
 | check_present | Check if the serial port exists during exporter initialization, disable if you are connecting to a dynamically created port (i.e. USB from your DUT) | bool  | no       | True    |
 | cps            | Characters per second throttling limit. When set, data transmission will be throttled to simulate slow typing. Useful for devices that can't handle fast input | float | no       | None    |
 
+## CLI Commands
+
+The pyserial driver provides two CLI commands for interacting with serial ports:
+
+### start_console
+
+Start an interactive serial console with direct terminal access.
+
+```bash
+j serial start-console
+```
+
+Exit the console by pressing CTRL+B three times.
+
+### pipe
+
+Pipe serial port data to stdout or a file. Automatically detects if stdin is piped and enables bidirectional mode.
+
+When stdin is used, commands are sent until EOF, then continues monitoring serial output until Ctrl+C.
+
+```bash
+# Log serial output to stdout
+j serial pipe
+
+# Log serial output to a file
+j serial pipe -o serial.log
+
+# Send command to serial, then continue monitoring output
+echo "hello" | j serial pipe
+
+# Send commands from file, then continue monitoring output
+cat commands.txt | j serial pipe -o serial.log
+
+# Force bidirectional mode (interactive)
+j serial pipe -i
+
+# Append to log file instead of overwriting
+j serial pipe -o serial.log -a
+
+# Disable stdin input even when piped
+cat data.txt | j serial pipe --no-input
+```
+
+#### Options
+
+- `-o, --output FILE`: Write serial output to a file instead of stdout
+- `-i, --input`: Force enable stdin to serial port (auto-detected if piped)
+- `--no-input`: Disable stdin to serial port, even if stdin is piped
+- `-a, --append`: Append to output file instead of overwriting
+
+Exit with Ctrl+C.
+
 ## API Reference
 
 ```{eval-rst}