Fix validation errors.

@aphillips you may want to check these, for future reference.

index.html

@@ -1061,7 +1061,7 @@ <h3>Choosing a definition of 'character'</h3>
 	</details>
 </div>
 
-<p>Visual rendering introduces the notion of a <a href="https://www.w3.org/TR/i18n-glossary/#def_glyph">glyph</a>. Glyphs are defined by [[ISO/IEC 9541-1]] as <q>a recognizable abstract graphic symbol which is independent of a specific design</q>. There is <em>not</em> a one-to-one correspondence between characters and glyphs:</p>
+<p>Visual rendering introduces the notion of a <a href="https://www.w3.org/TR/i18n-glossary/#def_glyph">glyph</a>. Glyphs are defined by ISO/IEC 9541-1 as <q>a recognizable abstract graphic symbol which is independent of a specific design</q>. There is <em>not</em> a one-to-one correspondence between characters and glyphs:</p>
 <ul>
 <li>A single character can be represented by multiple glyphs
 (each glyph is then part of the representation of that character). These glyphs
@@ -1451,9 +1451,9 @@ <h3>Designing character escapes</h3>
 		<table>
 			<thead>
 				<tr>
-					<th width="20%">Found In</th>
+					<th style="width:20%">Found In</th>
 					<th>Type</th>
-					<th width="15%">Example</th>
+					<th style="width:15%">Example</th>
 					<th>Description</th>
 				</tr>
 			</thead>