Switched Textbox to use a TextareaAutosize and removed custom resizing code

webapp/sass/components/_suggestion-list.scss

@@ -8,6 +8,7 @@
 
 .suggestion-list--top {
     position: absolute;
+    bottom: 100%;
 }
 
 .suggestion-list__content {

webapp/sass/layout/_post.scss

@@ -7,9 +7,7 @@
     line-height: 20px;
     min-height: 36px;
     overflow-x: hidden;
-    position: absolute;
     resize: none;
-    top: 0px;
     white-space: pre-wrap;
     word-wrap: break-word;