docs: Fix missing comma in props (#448)

### Fix or Enhancement?


- [ ] All tests passed


### Environment
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- NPM Version: Write here

Author: Timibadass

docs/guide/README.md

@@ -273,7 +273,7 @@ export default {
     chartdata: {
       type: Object,
       default: null
-    }
+    },
     options: {
       type: Object,
       default: null