fix: fixed emits heading

NataliaTepluhina · NataliaTepluhina · commit eac34572e7dc · 2021-01-14T09:50:04.000+01:00
diff --git a/src/guide/typescript-support.md b/src/guide/typescript-support.md
@@ -232,7 +232,7 @@ const Component = defineComponent({
 })
 ```
 
-## Annotating emits
+### Annotating emits
 
 We can annotate a payload for the emitted event. Also, all non-declared emitted events will throw a type error when called:
 
