docs: use sync onunload in examples (#221)

* docs: use sync onunload in examples

Refactor the onunload method to remove the async keyword.

* Adding one more that was missed

---------

Co-authored-by: Sigrunixia <sigrunixia@tenebrousdragon.com>

Author: mnaoumov

en/Plugins/Getting started/Anatomy of a plugin.md

@@ -7,7 +7,7 @@ export default class ExamplePlugin extends Plugin {
   async onload() {
     // Configure resources needed by the plugin.
   }
-  async onunload() {
+  onunload() {
     // Release any resources configured by the plugin.
   }
 }
@@ -33,7 +33,7 @@ export default class ExamplePlugin extends Plugin {
   async onload() {
     console.log('loading plugin')
   }
-  async onunload() {
+  onunload() {
     console.log('unloading plugin')
   }
 }

en/Plugins/User interface/Views.md

@@ -60,7 +60,7 @@ export default class ExamplePlugin extends Plugin {
     });
   }
 
-  async onunload() {
+  onunload() {
   }
 
   async activateView() {