Add physical interface notes and menu structure

src/SUMMARY.md

@@ -4,6 +4,7 @@
 - [Hardware](./chapter_2.md)
   - [Requirements](./chapter_2_1.md)
   - [GPIO Pinout](./chapter_2_2.md)
+  - [Physical Interface](./chapter_2_3.md)
 - [Software](./chapter_3.md)
   - [Operating System](./chapter_3_1.md)
     - [Networking](./chapter_3_1_1.md)
@@ -13,9 +14,7 @@
     - [peach-network](./chapter_3_2_3.md)
     - [peach-oled](./chapter_3_2_4.md)
     - [peach-stats](./chapter_3_2_5.md)
-  - [Interfaces](./chapter_3_3.md)
+  - [Web Interface](./chapter_3_3.md)
-    - [Physical Interface](./chapter_3_3_1.md)
-    - [Web Interface](./chapter_3_3_2.md)
   - [Configuration](./chapter_3_4.md)
 - [Contributor's Guide](./chapter_4.md)
 - [Licensing](./chapter_5.md)

src/chapter_2_3.md

@@ -0,0 +1,37 @@
+# Physical Interface
+
+The PeachCloud physical interface consists of a 5-way joystick, two push-buttons and a 128x64 OLED display.
+
+Development is taking place on the [AdaFruit 128x64 1.3" OLED Bonnet](https://www.adafruit.com/product/3531).
+
+_Note: the 5-way joystick may be replaced by four or five push-buttons in the release version of the physical interface._
+
+### Control
+
+The OLED display shows the PeachCloud logo on start-up. Pressing the `A` button (`#5`) loads the root of the menu system. The `UP` and `DOWN` directions on the joystick allow scrolling through the menu options, while the `A` button functions as Select and the `B` button (`#6`) functions as Back.
+
+Any button or joystick direction can be pressed to wake the display after selecting Display Off.
+
+### Menu Structure
+
+```
+.
+├── Networking
+│   └── MODE
+│   └── STATUS
+│   └── NETWORK
+│   └── IP
+│   └── SIGNAL
+│   └── Configuration
+│       ├── Client Mode
+│       └── Access Point Mode
+├── System Stats
+│   └── CPU
+│   └── MEM
+│   └── LOAD
+│   └── UPTIME
+│   └── DATA RX
+│   └── DATA TX
+├── Display Off
+└── Shutdown
+```

src/chapter_3_3.md

@@ -1 +1,7 @@
-# Interfaces
+# Web Interface
+
+[peach-web](https://github.com/peachcloud/peach-web) provides a web interface for monitoring and interacting with the PeachCloud device. This allows administration of the single-board computer (ie. Raspberry Pi) running PeachCloud, as well as the ssb-server and related plugins.
+
+**Stack**
+
+The peach-web stack currently consists of [Rocket](https://rocket.rs/) (Rust web framework), [Tera](https://tera.netlify.com/docs/installation/) (Rust template engine inspired by Jinja2 and the Django template language) and [Tachyons](https://tachyons.io/) (functional CSS library for humans).

src/chapter_3_3_1.md

@@ -1 +0,0 @@
-# Physical Interface