[css-position] Fix markup, fix level, prep for WD

Author: fantasai

css-position/Overview.bs

@@ -1,10 +1,11 @@
 <h1>CSS Positioned Layout Module Level 3</h1>
 
 <pre class='metadata'>
-Status: ED
+Status: WD
+Date: 2016-05-19
 Work Status: Exploring
 Shortname: css-position
-Level: 1
+Level: 3
 Group: csswg
 ED: https://drafts.csswg.org/css-position/
 TR: https://www.w3.org/TR/css3-positioning/
@@ -422,7 +423,7 @@ Relative positioning</h3>
   effect on the box (B2) that follows: B2 is given a position as if B1 were not
   offset and B2 is not re-positioned after B1’s offset is applied. This
   implies that relative positioning may cause boxes to overlap. However, if
-  relative positioning causes an 'overflow: auto' or 'overflow: scroll' box to
+  relative positioning causes an ''overflow: auto'' or ''overflow: scroll'' box to
   have overflow, the user agent must allow the user to access this content (at
   its offset position), which, through the creation of a scrolling mechanism,
   may affect layout.