[css-inline-3] Mark section informative, drop subheading, linkify ::first-letter.

Author: fantasai

css-inline-3/Overview.bs

@@ -568,12 +568,16 @@ Raised Initial Letters</h4>
 		<figcaption>Raised cap. The initial letter is the size of a 3-line initial, but does not drop.</figcaption>
 	</figure>
 
-<h3 id="selecting-drop-initials">Selecting Initial Letters</h3>
+<h3 id="selecting-drop-initials">
+Selecting Initial Letters</h3>
+
+	<em>This section is non-normative.</em>
 
 	Initial letters are typically a single letter, although
 	they may include punctuation or a sequence of characters which
 	are perceived by the user to be a single typographic unit.
-	The <code>::first-letter</code> pseudo-element, as defined in [[SELECT]],
+	The ''::first-letter'' pseudo-element,
+	defined in [[SELECT]] and [[CSS-PSEUDO-4]],
 	can be used to select the character(s) to be formatted as <a>initial letters</a>.
 
 	Authors who need more control over which characters are included in an initial letter,
@@ -595,15 +599,14 @@ Raised Initial Letters</h4>
 	</pre>
 	</div>
 
-<h4 id="initial-letter-punctuation">Initial Letter Punctuation</h4>
-
-	Since ''::first-letter'' selects punctuation before or after the first letter,
+	Note that
+	since ''::first-letter'' selects punctuation before or after the first letter,
 	these characters are included in the initial-letters when ''::first-letter'' is used.
 
 	<figure>
 		<img src="images/initial-letter-punctuation-quote.png" width="604"
 		     alt="Paragraph showing both opening quote and first letter set as three-line drop cap">
-		<figcaption>The <code>::first-letter</code> pseudo-element selects the quotation mark as well as the “M.”</figcaption>
+		<figcaption>The ''::first-letter'' pseudo-element selects the quotation mark as well as the “M”.</figcaption>
 	</figure>
 
 	Issue: Should there be a way to opt out of this behavior? See <a href="https://github.com/w3c/csswg-drafts/issues/310">Github Issue 310</a>.