Show friendly warning if snapd didn't update snap right for some reason

snap/scripts/telegram-launch

@@ -0,0 +1,16 @@
+#!/bin/sh
+
+if [ ! -d $SNAP/kf5/usr ]; then
+  runtime="kde-frameworks-5-core18"
+  slot="kde-frameworks-5-core18:kde-frameworks-5-core18-slot"
+
+  echo "You need to connect this snap to the $runtime snap."
+  echo ""
+  echo "You can do this with those commands:"
+  echo "snap install $runtime"
+  echo "snap refresh $runtime"
+  echo "snap connect $SNAP_NAME:kde-frameworks-5-plug $slot"
+  exit 1
+fi
+
+exec telegram-desktop "$@"

snap/snapcraft.yaml

@@ -15,7 +15,7 @@ architectures:
 
 apps:
   telegram-desktop:
-    command: telegram-desktop
+    command: telegram-launch
     common-id: org.telegram.desktop
     desktop: share/applications/telegramdesktop.desktop
     environment:
@@ -131,6 +131,12 @@ parts:
       - range-v3
       - xxhash
 
+  telegram-launcher:
+    plugin: dump
+    source: snap/scripts
+    organize:
+      telegram-launch: bin/telegram-launch
+
   patches:
     plugin: dump
     source: Telegram/Patches