fix: empty group title for board view

Author: junogueira

packages/react-notion-x/src/styles.css

@@ -1734,7 +1734,7 @@ svg.notion-page-icon {
 }
 
 .notion-board-th-empty {
-  margin-right: 4px;
+  margin-right: 6px;
   position: relative;
   top: 2px;
 }

packages/react-notion-x/src/third-party/collection-view-board.tsx

@@ -116,8 +116,8 @@ function Board({ collectionView, collectionData, collection, padding }) {
                       />
                     ) : (
                       <span>
-                        <EmptyIcon className='notion-board-th-empty' /> No
-                        Select
+                        <EmptyIcon className='notion-board-th-empty' />
+                        {`No ${schema.name}` || 'No Select'}
                       </span>
                     )}