[css-pseudo-4] Bikeshed fixes

Author: frivoal

css-pseudo-4/Overview.bs

@@ -367,13 +367,13 @@ First Letters and Associated Punctuation</h4>
     (ignoring the exclusion of word separators from <code>Zs</code>)
     represented as
     <code highlight="bnf" style="font-family: inherit">
-    (P (Zs|P)*)? (L|N|S) ((Zs|P−(Ps|Pd))* (P−(Ps|Pd))?</code>
+    (P (Zs|P)*)? (L\|N\|S) ((Zs|P−(Ps|Pd))* (P−(Ps|Pd))?</code>
     or, alternatively,
     <code highlight="bnf" style="font-family: inherit">
     (&#91;P] [Zs P]*)? [L N S] ([Zs [P--[Ps Pd]]]* [P--[Ps Pd]])?</code>
     <!-- this is not actually BNF, but it highlights better that way -->
 
-    ISSUE: Bikeshed is <a href="https://github.com/tabatkins/bikeshed/issues/2202">eating punctuation</a> in this note, which is not helpful.
+   <!-- Bikeshed is <a href="https://github.com/tabatkins/bikeshed/issues/2202">eating punctuation</a> in this note (unless escaped with undocumented escape sequences), which is not helpful. -->
 
     <pre class=railroad>
       Optional: