mark Synchthing-android as discontinued

currently it is

syncthing/syncthing-android#2064 (comment)

Author: boredsquirrel

data/apps/com.nutomic.syncthingandroid.json

@@ -18,8 +18,8 @@
         }
     ],
     "description": {
-        "en": "Syncthing is a continuous file synchronization program. It synchronizes files between two or more computers.",
-        "de": "Syncthing synchronisiert kontinuierlich Dateien zwischen einem oder mehreren Computeren oder Servern."
+        "en": "DISCONTINUED: Syncthing is a continuous file synchronization program. It synchronizes files between two or more computers.",
+        "de": "EINGESTELLT: Syncthing synchronisiert kontinuierlich Dateien zwischen einem oder mehreren Computeren oder Servern."
     },
     "icon": "https://raw.githubusercontent.com/syncthing/syncthing/main/assets/logo.ico",
     "categories": [