Add user guide

README.md

@@ -59,6 +59,10 @@ back to the other partition using the "Swap boot partition" button here https://
 
 See [Development](#development) below.
 
+## Usage
+
+See [the user guide](./USER_GUIDE.md) for instructions on operating CrossPoint.
+
 ## Development
 
 ### Prerequisites

USER_GUIDE.md

@@ -0,0 +1,78 @@
+# CrossPoint User Guide
+
+Welcome to the **CrossPoint** firmware. This guide outlines the hardware controls, navigation, and reading features of 
+the device.
+
+## 1. Hardware Overview
+
+The device utilises the standard buttons on the Xtink X4 in the same layout:
+
+### Button Layout
+| Location        | Buttons                                    |
+|-----------------|--------------------------------------------|
+| **Bottom Edge** | **Back**, **Confirm**, **Left**, **Right** |
+| **Right Side**  | **Power**, **Volume Up**, **Volume Down**  |
+
+---
+
+## 2. Power & Startup
+
+### Power On / Off
+
+To turn the device on or off, **press and hold the Power button for 1 full second**.
+
+### First Launch
+
+Upon turning the device on for the first time, you will be placed on the **Book Selection Screen** (File Browser).
+
+> **Note:** On subsequent restarts, the firmware will automatically reopen the last book you were reading.
+
+---
+
+## 3. Book Selection
+
+The Home Screen acts as a folder and file browser.
+
+* **Navigate List:** Use **Left** (or **Volume Up**), or **Right** (or **Volume Down**) to move the selection cursor up 
+  and down through folders and books.
+* **Open Selection:** Press **Confirm** to open a folder or read a selected book.
+
+---
+
+## 4. Reading Mode
+
+Once you have opened a book, the button layout changes to facilitate reading.
+
+### Page Turning
+| Action            | Buttons                              |
+|-------------------|--------------------------------------|
+| **Previous Page** | Press **Left** _or_ **Volume Up**    |
+| **Next Page**     | Press **Right** _or_ **Volume Down** |
+
+### Chapter Navigation
+* **Next Chapter:** Press and **hold** the **Right** (or **Volume Down**) button briefly, then release.
+* **Previous Chapter:** Press and **hold** the **Left** (or **Volume Up**) button briefly, then release.
+
+### System Navigation
+* **Return to Home:** Press **Back** to close the book and return to the Book Selection screen.
+* **Chapter Menu:** Press **Confirm** to open the Table of Contents/Chapter Selection screen.
+
+---
+
+## 5. Chapter Selection Screen
+
+Accessible by pressing **Confirm** while inside a book.
+
+1.  Use **Left** (or **Volume Up**), or **Right** (or **Volume Down**) to highlight the desired chapter.
+2.  Press **Confirm** to jump to that chapter.
+3.  *Alternatively, press **Back** to cancel and return to your current page.*
+
+---
+
+## 6. Current Limitations & Roadmap
+
+Please note that this firmware is currently in active development. The following features are **not yet supported** but
+are planned for future updates:
+
+* **Images:** Embedded images in e-books will not render.
+* **Text Formatting:** There are currently no settings to adjust font type, size, line spacing, or margins.