docs/  (335 Markdown files, 21 directories; .md suffix omitted)
Rule: an entry like unit/env means docs/unit/env.md; entries ending in / are directories.
- root: COPYRIGHT
  - advanced/: camera, code_scanner, dl, image, jpg
    - usb/: _overview
      - device/: keyboard, mouse
  - base/: atom_can, atom_gps, atom_socket, audio35, display, dtu_lorawan, dtu_lorawan_rui3, dtu_nbiot, dtu_nbiot2
           dtu_nbiot2v11, echo, echo_pyramid, gpsv2, hdriver, motion, pwm, qrcode, qrcode2, rs232, rs485, speaker
           stepmotor, tfcard
  - cap/: lora1262, lora868
  - chain/: angle, chainbus, encoder, joystick, key, mono, rgb, tof, unit_bus
  - contribute/: template
  - controllers/: airq, atoms3-lite, atoms3r_cam, cardputer, coreink, dinmeter, dualkey, nesso-n1, paper, stackchan
                  stamplc, sticks3, stopwatch
  - get-started/: _overview
  - hardware/: adc, als, button, can, display, imu, ir, lora, mic, pin, pwr485, pwrcan, rotary, scd40, sen55, sht30
               speaker, touch, uart, wdt
  - hat/: adc, cardkb, dac, dac2, dlight, env, finger, heart, joyc, joystick, mini_encoder, mini_joy, ncir, neoflash
          pir, servo, servo8, speaker, speaker2, thermal, tof, vibrator
  - iot-devices/: _overview, switchc6
  - m5ui/: _overview, arc, bar, button, buttonmatrix, calendar, canvas, chart, checkbox, dropdown, image, keyboard
           label, led, line, list, menu, msgbox, page, roller, scale, slider, spinbox, spinner, switch, table, tabview
           textarea, win
  - module/: 4in8out, ain4, asr, audio, bala2, cc1101, commu, dc_motor, display, dmx, dualkmeter, ecg, encoder4_motor
             fan, gateway_h2, gnss, goplus2, gps, gpsv2, grbl, hmi, lan, llm, lora, lora868_v12, lorawan868
             lorawan_rui3, lte, nbiot, odrive, plus, pm25, pps, pwrcan, qrcode, rca, relay_2, rs232, servo2
             step_motor_driver, usb, zigbee
  - quick-reference/: get-started, usb-mode
  - software/: easysocket, modbus, modbus.rtu.master, modbus.rtu.slave, modbus.tcp.client, modbus.tcp.server
               requests2, tcp.client, tcp.server, udp.client, udp.server, umqtt.default, umqtt
  - stamplc/: ac, poe
  - system/: audio, audio.player, audio.recorder, bleuart.client, bleuart, bleuart.server, m5ble, m5espnow, power
             time, wlan.ap, wlan.sta
  - tab5/: keyboard
  - unit/: ac_measure, accel, acssr, adc, adc_v11, ain4, angle, angle8, asr, audioplayer, bldc_driver, bps, button
           buzzer, bytebutton, byteswitch, can, cardkb, cardkb2, cat1cn, catch, co2, co2l, color, dac, dac2, dcssr
           dds, digi_clock, dlight, dmx, dualbutton, earth, encoder, encoder8, env, envpro, extencoder, extio, extio2
           fader, finger, fingerprint2, flash_light, gateway_h2, glass, glass2, gps_v11, grove2grove, hall_effect
           hbridge, heart, id, imu, imupro, ina226, ir, joystick, joystick2, key, kmeter, kmeter_iso, laser_rx
           laser_tx, lcd, light, limit, lora_e220, lora_e220_433, lorawan_rui3, midi, minioled, miniscale, mq, mqtt
           mqttpoe, nbiot, nbiot2, ncir, ncir2, neco, nfc, oled, op180, op90, pdm, pir, puzzle, qrcode, rca
           reflective_ir, relay, relay2, relay4, rf433r, rf433t, rfid, rgb, roller485, rollercan, rtc, scales, scroll
           servo180, servo360, servos8, ssr, step16, synth, thermal, timerpwr, tmos, tof, tof4m, tof90, tube_pressure
           tvoc, uhf_rfid, ultrasonic, ultrasonic_io, uwb, vibrator, watering, weight, weight_i2c, zigbee
  - widgets/: _overview, circle, image+, image, label+, label
