AC-375: WYSIWYG panel resize small in category

- change default size to 250

Author: krissyhiserote

lib/web/mage/adminhtml/wysiwyg/tiny_mce/tinymce5Adapter.js

@@ -270,7 +270,7 @@ define([
             };
 
             // Set default initial height
-            settings['min_height'] = this.config.tinymce['min_height'] ? this.config.tinymce['min_height'] : 400;
+            settings['min_height'] = this.config.tinymce['min_height'] ? this.config.tinymce['min_height'] : 250;
 
             if (this.config.skin) {
                 settings.skin = this.config.skin;