fixed GFM references not working

[ci skip]

app/assets/javascripts/issue_show/components/fields/description.vue

@@ -43,7 +43,8 @@
         aria-label="Description"
         v-model="formState.description"
         ref="textarea"
-        slot="textarea">
+        slot="textarea"
+        placeholder="Write a comment or drag your files here...">
       </textarea>
     </markdown-field>
   </div>

app/assets/javascripts/vue_shared/components/markdown/field.vue

@@ -62,7 +62,7 @@
       /*
         GLForm class handles all the toolbar buttons
       */
-      return new gl.GLForm($(this.$refs['gl-form']));
+      return new gl.GLForm($(this.$refs['gl-form']), true);
     },
   };
 </script>