Added an issue for layout-grid-mode: baseline

Author: kojiishi

css-line-grid/Overview.html

@@ -469,7 +469,9 @@ <h3 id=layout-grid-mode-prop><span class=secno>3.1. </span>Grid Mode: the
         and with after margin if last.
         -->
     The height is the height of the line box. Increasing heights to fit to
-    grids is done by increasing the computed height of the line box.
+    grids is done by increasing the computed height of the line box. <span
+    class=issue>How to make this value work well with images, headings, etc.
+    is still an issue</span>
 
    <dt><dfn id=block title="layout-grid-mode::block">&lsquo;<code
     class=css>block</code>&rsquo;</dfn>

css-line-grid/Overview.src.html

@@ -299,6 +299,7 @@ <h3 id="layout-grid-mode-prop">Grid Mode: the 'layout-grid-mode' property</h3>
         The height is the height of the line box.
         Increasing heights to fit to grids is done by
         increasing the computed height of the line box.
+        <span class="issue">How to make this value work well with images, headings, etc. is still an issue</span>
       </dd>
     <dt><dfn title="layout-grid-mode::block">''block''</dfn></dt>
       <dd>Align blocks to the line grids.