Create example docs

docs/custom/ping_pong.js

@@ -0,0 +1,10 @@
+const fs = require('fs-extra');
+
+module.exports = {
+  category: 'Examples',
+  name: 'Ping Pong',
+  data:
+`\`\`\`js
+${fs.readFileSync('./docs/custom/examples/ping_pong.js').toString('utf-8')}
+\`\`\``,
+};