[WIP] Revamp README.md

Author: pynicolas

README.md

@@ -7,34 +7,58 @@ FairScan is an Android app to scan documents. It aims to be simple and respectfu
 - The scanning process should be obvious.
 - The app should automatically handle all image processing and PDF generation tasks.
 
-[![Google Play]][https://play.google.com/store/apps/details?id=org.fairscan.app]
-[![GitHub releases]][releases]
-[![fairscan.org]][https://fairscan.org]
+[Google Play](https://play.google.com/store/apps/details?id=org.fairscan.app)
+[GitHub releases](releases)
+[fairscan.org](https://fairscan.org)
 
 <p>
-  <img src="screenshots/step-1.webp" width="30%" style="margin:1%">
-  <img src="screenshots/step-2.webp" width="30%" style="margin:1%">
-  <img src="screenshots/step-3.webp" width="30%" style="margin:1%">
+  <img src="screenshots/step-1.webp" width="30%">
+  <img src="screenshots/step-2.webp" width="30%">
+  <img src="screenshots/step-3.webp" width="30%">
 </p>
 
 ## Features
 
-- Capture from the device camera
-- Automatic document detection using segmentation
-- Perspective correction
-- PDF export
-- 100% offline, no ads, no tracking, no account
+- Automatic document detection (using a custom image segmentation model)
+- Automatic perspective correction
+- Automatic image enhancement
 
-## Philosophy
+## Compatibility
 
-Most document scanner apps are cluttered, invasive, or frustrating to use.  
-FairScan aims to be a simple, efficient and respectful alternative.
+FairScan should be compatible with all devices that:
+- run Android 8.0 or a more recent version
+- have a camera
 
+## Privacy
+
+- All data stay on the device. As of today, FairScan doesn't use any access to internet.
+- Minimal permissions:
+  - Camera
+  - WRITE_EXTERNAL_STORAGE: only on Android 8 and 9 to save generated PDFs in the Download directory.
+- Zero trackers.
+
+## Main dependencies
+
+- Jetpack Compose for the user interface
+- CameraX to capture images from the camera
+- LiteRT to run the segmentation model for automatic document detection
+- OpenCV for:
+  - perspective correction
+  - image enhancement
+- PDFBox for PDF generation
+
+Kudos to the developers of those projects!
 
 ## Build instructions
 
+To build an APK:
+```bash
+./gradlew clean check assembleRelease
+```
+
+To build an Android App Bundle:
 ```bash
-./gradlew assembleRelease
+`./gradlew clean check :app:bundleRelease
 ```
 
 ## License