tweak inherit wording

Author: fantasai

css3-background/Overview.html

@@ -338,7 +338,7 @@ <h2 id=values><span class=secno>2 </span>Values</h2>
   <p>All other values are defined in CSS Level 2 Revision 1 <a href="#CSS21"
    rel=biblioentry>[CSS21]<!--{{!CSS21}}--></a>.
 
-  <p>All properties defined in this specification accept the <a
+  <p>All properties defined in this specification also accept the <a
    href="http://www.w3.org/TR/CSS21/cascade.html#value-def-inherit">inherit</a>
    keyword as their value, but for readability it has not been listed
    explicitly.

css3-background/Overview.src.html

@@ -141,7 +141,7 @@ <h2>Values</h2>
 
 <p>All other values are defined in CSS Level 2 Revision 1 [[!CSS21]].</p>
 
-<p>All properties defined in this specification accept the
+<p>All properties defined in this specification also accept the
 <a href="http://www.w3.org/TR/CSS21/cascade.html#value-def-inherit">inherit</a>
 keyword as their value, but for readability it has not been listed explicitly.