Add demo.gif to vscode ignores

.vscodeignore

@@ -12,6 +12,7 @@ vsc-extension-quickstart.md
 **/*.map
 **/*.ts
 **/.vscode-test.*
+demo.gif
 
 !node_modules/@vscode/codicons/dist/codicon.css
 !node_modules/@vscode/codicons/dist/codicon.ttf