Add screenshots from docs

DESCRIPTION.md

@@ -5,11 +5,13 @@ Syncthing replaces proprietary sync and cloud services with something open, trus
 ### Features
 
 #### Secure & Private
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 - **Private.** None of your data is ever stored anywhere else other than on your computers. There is no central server that might be compromised, legally or illegally.
 - **Encrypted.** All communication is secured using TLS. The encryption used includes perfect forward secrecy to prevent any eavesdropper from ever gaining access to your data.
 - **Authenticated.** Every node is identified by a strong cryptographic certificate. Only nodes you have explicitly allowed can connect to your cluster.
 
 #### Easy to Use
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 Syncthing is still in development, although a large number of features have already been implemented:
 
 - **Web GUI.** Configure and monitor Syncthing via a responsive and powerful interface accessible via your browser.
@@ -18,6 +20,7 @@ Syncthing is still in development, although a large number of features have alre
 - **Powerful.** Synchronize as many folders as you need with different people.
 
 #### Native GUIs & Integrations
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 - **Windows** tray utility, filesystem watcher & launcher: [SyncTrayzor](https://github.com/canton7/SyncTrayzor/releases/latest)
 - **Cross-platform** GUI wrapper: [Syncthing-GTK](https://github.com/syncthing/syncthing-gtk/releases/latest)
 - **Android** app: [Syncthing App](https://f-droid.org/repository/browse/?fdid=com.nutomic.syncthingandroid)