Allow keyboard modal form submission (#38826)

app/javascript/mastodon/components/form_fields/text_input.module.scss

@@ -1,7 +1,6 @@
 .input {
   box-sizing: border-box;
   display: block;
-  resize: vertical;
   width: 100%;
   padding: 10px 16px;
   font-family: inherit;
@@ -50,6 +49,10 @@
   }
 }
 
+textarea.input {
+  resize: vertical;
+}
+
 .iconWrapper {
   position: relative;
 }