[selectors] Add issue for the parsing algo.

Author: tabatkins

selectors/Overview.bs

@@ -3144,6 +3144,8 @@ Calculating a selector's specificity</h2>
 <h2 id="grammar"><span id="formal-syntax"></span>
 Grammar</h2>
 
+	Issue: Rewrite this whole danged thing in terms of Syntax parsing algos instead.
+
 	The grammar below defines the syntax of Selectors.
 	It is applied to a stream of tokens,
 	as returned by the tokenizer defined in [[!CSS3SYN]].

selectors/Overview.html

@@ -3252,6 +3252,8 @@ <h2 class="heading settled heading" data-level=15 id=specificity><span class=sec
 <h2 class="heading settled heading" data-level=16 id=grammar><span class=secno>16 </span><span class=content><span id=formal-syntax></span>
 Grammar</span><a class=self-link href=#grammar></a></h2>
 
+<p class=issue id=issue-240af3df><a class=self-link href=#issue-240af3df></a>	 Rewrite this whole danged thing in terms of Syntax parsing algos instead.
+
 <p>	The grammar below defines the syntax of Selectors.
 	It is applied to a stream of tokens,
 	as returned by the tokenizer defined in <a data-biblio-type=normative data-link-type=biblio href=#css3syn title=css3syn>[CSS3SYN]</a>.
@@ -3765,4 +3767,6 @@ <h2 class="no-num heading settled" id=issues-index><span class=content>Issues In
 		Should "null segments" count as matching, or not?
 
 
-<a href=#issue-3f3b379a> ↵ </a></div></div>
+<a href=#issue-3f3b379a> ↵ </a></div><div class=issue>	 Rewrite this whole danged thing in terms of Syntax parsing algos instead.
+
+<a href=#issue-240af3df> ↵ </a></div></div>