[css-grid-2] Update abstract.

Author: fantasai

css-grid-2/Overview.bs

@@ -9,7 +9,7 @@ ED: https://drafts.csswg.org/css-grid-2/
 Editor: Tab Atkins Jr., Google, http://www.xanthir.com/contact/, w3cid 42199
 Editor: Elika J. Etemad / fantasai, Invited Expert, http://fantasai.inkedblade.net/contact, w3cid 35400
 Editor: Rossen Atanassov, Microsoft, ratan@microsoft.com, w3cid 49885
-Abstract: This CSS module defines a two-dimensional grid-based layout system, optimized for user interface design. In the grid layout model, the children of a grid container can be positioned into arbitrary slots in a predefined flexible or fixed-size layout grid.
+Abstract: This CSS module defines a two-dimensional grid-based layout system, optimized for user interface design. In the grid layout model, the children of a grid container can be positioned into arbitrary slots in a predefined flexible or fixed-size layout grid. Level 2 expands Grid by adding “subgrid” capabilities for nested grids to participate in the sizing of their parent grids; and aspect-ratio–controlled gutters.
 </pre>
 
 Introduction {#intro}
@@ -21,7 +21,7 @@ It adds the following features:
   * Subgrids
   * Aspect-ratio-controlled gutters
 
-Issue: There's currently also an issue about Masonry layout, but it's unlikely to make it for L2.
+Issue: The full text of the Grid specification will be folded in for CR.
 
 <h2 id="grid-model">
 Grid Containers</h2>