add docs for running meshchat on raspberry pi

docs/meshchat_raspberry_pi.md

@@ -0,0 +1,90 @@
+# MeshChat on Raspberry Pi
+
+A simple guide to install [MeshChat](https://github.com/liamcottle/reticulum-meshchat) on a Raspberry Pi.
+
+This would allow you to connect an [RNode](https://github.com/markqvist/RNode_Firmware) (such as a Heltec v3) to the Rasbperry Pi via USB, and then access the MeshChat Web UI from another machine on your network.
+
+My intended use case is to run the Pi + RNode combo from my solar-powered shed, and access the MeshChat Web UI via WiFi.
+
+## Install Raspberry Pi OS
+
+If you haven't already done so, the first step is to install Raspberry Pi OS onto an sdcard, and then boot up the Pi. Once booted, follow the below commands.
+
+## Update System
+
+```
+sudo apt update
+sudo apt upgrade
+```
+
+## Install System Dependencies
+
+```
+sudo apt install git
+sudo apt install python3-pip
+```
+
+## Install NodeJS v22
+
+```
+curl -fsSL https://deb.nodesource.com/gpgkey/nodesource-repo.gpg.key | sudo gpg --dearmor -o /usr/share/keyrings/nodesource.gpg
+NODE_MAJOR=22
+echo "deb [signed-by=/usr/share/keyrings/nodesource.gpg] https://deb.nodesource.com/node_$NODE_MAJOR.x nodistro main" | sudo tee /etc/apt/sources.list.d/nodesource.list
+sudo apt update
+sudo apt install nodejs
+```
+
+## Install MeshChat
+
+```
+git clone https://github.com/liamcottle/reticulum-meshchat
+cd reticulum-meshchat
+pip install -r requirements.txt --break-system-packages
+npm install --omit=dev
+npm run build-frontend
+```
+
+## Run MeshChat
+
+```
+python meshchat.py --headless --host 0.0.0.0
+```
+
+## Configure Service
+
+Adding a `systemd` service will allow MeshChat to run in the background when you disconnect from the Pi's terminal.
+
+```
+sudo nano /etc/systemd/system/reticulum-meshchat.service
+```
+
+```
+[Unit]
+Description=reticulum-meshchat
+After=network.target
+StartLimitIntervalSec=0
+
+[Service]
+Type=simple
+Restart=always
+RestartSec=1
+User=liamcottle
+Group=liamcottle
+WorkingDirectory=/home/liamcottle/reticulum-meshchat
+ExecStart=/usr/bin/env python /home/liamcottle/reticulum-meshchat/meshchat.py --headless --host 0.0.0.0
+
+[Install]
+WantedBy=multi-user.target
+```
+
+> Note: Make sure to update the usernames in the service file if needed.
+
+```
+sudo systemctl enable reticulum-meshchat.service
+sudo systemctl start reticulum-meshchat.service
+sudo systemctl status reticulum-meshchat.service
+```
+
+You should now be able to access MeshChat via your Pi's IP address.
+
+> Note: Don't forget to include the default port `8000`