Adding documentation for chatter and its keypad (#1283)

* adding documentation for chatter and its keypad

* restore lock file

* updating the doc to add the TAB and RIGHT buttons mapping

* fix SHIFT bug

* change images format

* convert images to webp

---------

Co-authored-by: Tommy Ekstrand <tekstrand@users.noreply.github.com>

docs/configuration/module/canned-message.mdx

@@ -41,6 +41,7 @@ Input event sources accepted by the canned message module.
 |  `rotEnc1`   |                         Basic Rotary Encoder                         |
 | `upDownEnc1` |     Up Down Encoder (use this also for RAK14006 Rotary Encoder)      |
 |   `cardkb`   |           M5 Stack CardKB (this covers RAK14004 Keymatrix)           |
+|  `serialkb`  |                        Chatter serial keypad                         |
 
 ### Rotary Encoder Enabled
 

docs/hardware/devices/chatter/buttons.mdx

@@ -0,0 +1,24 @@
+---
+id: keypad
+title: Chatter2 Hardware keypad
+sidebar_label: Keypad
+sidebar_position: 1
+---
+
+## Functionality
+
+The layout is the one printed on the Chatter sticker
+
+![Chatter Keypad](/img/hardware/chatter_keypad.webp)
+
+Each button can be pressed up to 4 times in quick succession to access the second third and fourth character listed under it.
+The shift button cycle between lower case letters, upper case, and numbers.
+
+
+
+The top/left button (labelled UP/LEFT) is assigned to UP and allows the user to access preregistered canned messages (SELECT to send and CANCEL to go back).
+The next button (labelled DOWN/RIGHT) is assigned to RIGHT.
+The BACKSPACE button is assigned to the TAB function when SHIFT has been pressed once.
+To select a destination, use the TAB button (press SHIFT once then BACKSPACE) to highlight the destination field. Then use the RIGHT key to cycle through available destinations. (Press SHIFT again to return the first function of each key)
+
+Simply starting to type a text using the letter key will automatically open a free text input panel and allow the user to write the message to send using the SELECT key.

docs/hardware/devices/chatter/index.mdx

@@ -0,0 +1,49 @@
+---
+id: chatter
+title: Chatter device
+sidebar_label: Chatter
+sidebar_position: 13
+---
+
+The Chatter is a DIY kit sold by CircuitMess. It is intended as a STEM toy and comes with a nice firmware allowing to connect to other Chatter and exchange messages.
+However, it's HW is similar to most Meshtastic nodes, with an ESP32, a LoRa chip, a screen and few buttons.
+
+![Chatter V1.0](/img/hardware/chatter.webp)
+
+There's two versions of the Chatter available with very few actual differences.
+Chatter V2.0 sports:
+ - one button (Button 15) wired directly to the ESP32 (pin 36)
+ - an i2c port to easily connect a GPS
+ - a different routing
+ 
+Both versions are fully supported by Meshastic with the same firmware. 
+
+The Meshtastic firmware works with the stock hardware, however, the LLCC68 LoRa chip cripples the RF capability of the device. As is, the Chatter can only communicate on the Medium-Slow channel. 
+Switching the chip with the pin-compatible and more capable Heltec RA62 (as mentioned in this Github issue https://github.com/meshtastic/firmware/issues/2896) unlock the full potential of the device.
+
+
+## Specifications
+
+- **MCU**
+  - ESP32 WROOM (WiFi & Bluetooth)
+    - Bluetooth 4.2
+- **LoRa Transceiver**
+  - LLCC68
+- **Frequency options**
+  - EU-868 MHz
+- **Keypad**
+  - 74HC165 based serial keypad
+- **Connectors**
+  - USB-C
+
+## Features
+
+- Integrated Keypad for on device message input
+- 1.3 inch OLED screen
+- Optional I2C GPS Module
+
+## Resources
+
+- Firmware file: `firmware-chatter2-X.X.X.xxxxxxx.bin`
+- [Official build guide](https://circuitmess.com/blogs/resources/chatter-build-guide)
+