message: strikethrough & underline deletions & insertions
diff: @@ -46,11 +46,13 @@ limitations under the License.
  .mx_EditHistoryMessage_deletion {
  color: rgb(255, 76, 85);
  background-color: rgba(255, 76, 85, 0.1);
  + text-decoration: line-through;
  }
  .mx_EditHistoryMessage_insertion {
  color: rgb(26, 169, 123);
  background-color: rgba(26, 169, 123, 0.1);
  + text-decoration: underline;
  }
  .mx_EventTile_line, .mx_EventTile_content {
  