fix(textarea): autogrow playground can scroll to the top of contents (#3219)

Author: sean-perkins

static/usage/v6/textarea/autogrow/demo.html

@@ -11,6 +11,8 @@
 
     <style>
       .container {
+        display: block;
+
         padding: 0 40px;
       }
 

static/usage/v7/textarea/autogrow/demo.html

@@ -11,6 +11,8 @@
 
     <style>
       .container {
+        display: block;
+
         padding: 0 40px;
       }