add info to README

README.md

@@ -1,17 +1,35 @@
-# Pi-Apps ![logo](https://github.com/Botspot/pi-apps/blob/master/icons/logo-64.png?raw=true)
+# Pi-Apps   ![logo](https://github.com/Botspot/pi-apps/blob/master/icons/logo-64.png?raw=true)
 ## Raspberry Pi App Store for Open Source Projects
 
 There are many open-source, community-developed software projects for Raspberry Pi, yet very few people know about them. Pi-Apps aims to improve that, functioning as a software catalog and standardizing installation.
 
-**Please note that Pi-Apps is very new and is a work in progress.** Keep that in mind if you encounter an error.
+**Pi-Apps is very new and is a work in progress.** Please [report](https://github.com/Botspot/pi-apps/issues/new) any errors you encounter.
 
-### To install Pi Apps:
+### To install Pi Apps
 ```
 git clone https://github.com/Botspot/pi-apps
 /home/pi/pi-apps/install
 ```
 The install script ensures YAD is installed and creates a menu button. Nothing is modified outside your home directory.
-### To run Pi Apps:
+### To run Pi Apps
 Menu -> Accessories -> Pi Apps, or type `./pi-apps/gui`.
-
+### Basic usage
-
+- This is the **main window**:  
+![main window](https://github.com/Botspot/pi-apps/blob/master/icons/screenshots/main%20window.png?raw=true)  
+Use the main window to quickly browse the selection of apps and easily install them.  
+- If you double-click an app, or select and app and click Details, you will see the **Details window**.  
+![details](https://github.com/Botspot/pi-apps/blob/master/icons/screenshots/details%20window.png?raw=true)  
+- The **updater window** may pop up when you launch Pi-Apps:  
+![updates](https://github.com/Botspot/pi-apps/blob/master/icons/screenshots/updates%20available.png?raw=true)  
+Unless you have a very good reason not to, clicking 'Update now' is strongly recommended.  
+- Pi-Apps **Settings** can be configured by launching Menu -> Preferences -> Pi-Apps Settings.  
+![settings](https://github.com/Botspot/pi-apps/blob/master/icons/screenshots/settings.png?raw=true)  
+- If you click **New App** in Settings, you can easily create your own Apps with a wizard-style sequence of windows.  
+![create app](https://github.com/Botspot/pi-apps/blob/master/icons/screenshots/create%20app.png?raw=true)  
+It helps you select an icon, create & debug install/uninstall scripts, write a description, and more.  
+### How it works
+ - Each 'App' is simply a small `install` script, `uninstall` script, two icon sizes, and two text files containing the description and a website URL.
+ - Each App is stored in its own separate directory. `/home/pi/pi-apps/apps/` holds all these app directories. The Zoom app, for example, would be located at `/home/pi/pi-apps/apps/Zoom/`.
+ - Because of the contained nature of each app folder, it's really easy to 'package' your own apps: just put the folder in a ZIP file and send it to friends. (or upload it as a [new issue](https://github.com/Botspot/pi-apps/issues/new) so your app can be added to Pi-Apps)
+ - When you click Install, the selected App's install script is executed.
+ - When you click Uninstall, the selected App's uninstall script is executed.