Update events.md - fix options-api class

Author: leoelz

src/guide/components/events.md

@@ -176,7 +176,7 @@ export default {
 
 </div>
 
-The <span class="composition-api">`defineEmits()` macro</span><span class="composition-api">`emits` option</span> also supports an object syntax, which allows us to perform runtime validation of the payload of the emitted events:
+The <span class="composition-api">`defineEmits()` macro</span><span class="options-api">`emits` option</span> also supports an object syntax, which allows us to perform runtime validation of the payload of the emitted events:
 
 <div class="composition-api">