clan-app: Finish flash view. clan-cli: Flash cli now verifies if language and keymap are valid.

pkgs/webview-ui/app/gtk.webview.js

@@ -43,7 +43,7 @@ fs.readFile(manifestPath, { encoding: "utf8" }, (err, data) => {
                 console.log(`Rewriting CSS url(): ${asset.url} to ${res}`);
                 return res;
               },
-            })
+            }),
           )
           .process(css, {
             from: `dist/${cssEntry}`,