Upload port required

If I don't specify upload port, I get an error message:

Processing pico (platform: raspberrypi; board: pico; framework: arduino)
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------
Verbose mode can be enabled via `-v, --verbose` option
CONFIGURATION: https://docs.platformio.org/page/boards/raspberrypi/pico.html
PLATFORM: Raspberry Pi RP2040 (0.0.0+sha.aa251bf) > Raspberry Pi Pico
HARDWARE: RP2040 133MHz, 264KB RAM, 2MB Flash
DEBUG: Current (cmsis-dap) External (cmsis-dap, raspberrypi-swd, stlink)
PACKAGES: 
 - framework-arduino-mbed 2.0.0 
 - tool-openocd-raspberrypi 2.1100.0 (11.0) 
 - tool-rp2040tools 1.0.2 
 - toolchain-gccarmnoneeabi 1.90201.191206 (9.2.1)
LDF: Library Dependency Finder -> http://bit.ly/configure-pio-ldf
LDF Modes: Finder ~ chain, Compatibility ~ soft
Found 47 compatible libraries
Scanning dependencies...
No dependencies
Building in release mode
Checking size .pio/build/pico/firmware.elf
Advanced Memory Usage is available via "PlatformIO Home > Project Inspect"
RAM:   [==        ]  18.7% (used 50500 bytes from 270336 bytes)
Flash: [          ]   3.5% (used 73056 bytes from 2097152 bytes)
Configuring upload protocol...
AVAILABLE: cmsis-dap, raspberrypi-swd, stlink
Looking for upload port...

Warning! Please install `99-platformio-udev.rules`. 
More details: https://docs.platformio.org/page/faq.html#platformio-udev-rules

Error: Please specify `upload_port` for environment or use global `--upload-port` option.
For some development platforms it can be a USB flash drive (i.e. /media/<user>/<device name>)
*** [upload] Explicit exit, status 1
===================================================================== [FAILED] Took 1.12 seconds ====

If it's really the case, it would be good to mention this in the example or docs.

Start with the Raspberry Pi Pico example and documentation around upload configuration, using the provided PlatformIO upload log and board documentation link as context. Done means the example or docs clearly state when upload_port must be specified and how users should provide it.