Validate settings before run

src/platform.rs

@@ -10,6 +10,14 @@ where
 
     fn get_shortcuts(&self) -> Result<Vec<T>, E>;
 
+    fn settings_valid(&self) -> SettingsValidity;
+
     #[cfg(target_os = "linux")]
     fn create_symlinks(&self) -> bool;
 }
+
+
+pub enum SettingsValidity{
+    Valid,
+    Invalid{reason:String},
+}