fix: use proper flat vnode format in example. (vuejs#223)

LinusBorg · Thorsten Luenborg · web-flow · commit 80b1723edc84 · 2020-07-18T15:25:55.000+03:00
The last example in the render function migration guide
used old Vue 2 syntax in a few places.

Co-authored-by: Thorsten Luenborg &lt;t.luneborg@googlemail.com&gt;
diff --git a/src/guide/migration/render-function-api.md b/src/guide/migration/render-function-api.md
@@ -116,9 +116,9 @@ In 3.x, the entire VNode props structure is flattened. Using the example from ab
 {
   class: ['button', 'is-outlined'],
   style: { color: '#34495E' },
-  attrs: { id: 'submit' },
+  id: 'submit',
   innerHTML: '',
-  on: { click: submitForm },
+  onClick: submitForm,
   key: 'submit-button'
 }
 ```

Original file line number	Diff line number	Diff line change
`@@ -116,9 +116,9 @@ In 3.x, the entire VNode props structure is flattened. Using the example from ab`
`116`	`116`	`{`
`117`	`117`	`class: ['button', 'is-outlined'],`
`118`	`118`	`style: { color: '#34495E' },`
`119`		`- attrs: { id: 'submit' },`
	`119`	`+ id: 'submit',`
`120`	`120`	`innerHTML: '',`
`121`		`- on: { click: submitForm },`
	`121`	`+ onClick: submitForm,`
`122`	`122`	`key: 'submit-button'`
`123`	`123`	`}`
`124`	`124`	```