make search box ever so slightly wider

R=rsc
http://go/go-review/1024036

lib/godoc/godoc.html

@@ -107,7 +107,7 @@
     <li class="blank">&nbsp;</li>
     <li class="navhead">Go code search</li>
     <form method="GET" action="/search" class="search">
-    <input type="search" name="q" value="{Query|html}" size="25" style="width:75%; max-width:200px" />
+    <input type="search" name="q" value="{Query|html}" size="25" style="width:80%; max-width:200px" />
     <input type="submit" value="Go" />
     </form>