Switch A/B order in content-descriptor sub-type definition (#260)

Makes it match the table

index.html

@@ -910,9 +910,9 @@ <h5><code>&lt;content-descriptor&gt;</code> values</h5>
             </div>
             <p><code>&lt;<a>content-descriptor</a>&gt;</code> has values that are delimiter separated ordered lists
               of tokens.</p>
-            <p>A <code>&lt;<a>content-descriptor</a>&gt;</code> value <em>A</em> is a <dfn data-abbr="sub-type">content descriptor sub-type</dfn>
-              of another <code>&lt;content-descriptor&gt;</code> value <em>B</em> if B's ordered list of <a>descriptor-tokens</a> is
-              present at the beginning of A's ordered list of <a>descriptor-tokens</a>.
+            <p>A <code>&lt;<a>content-descriptor</a>&gt;</code> value <em>B</em> is a <dfn data-abbr="sub-type">content descriptor sub-type</dfn>
+              of another <code>&lt;content-descriptor&gt;</code> value <em>A</em> if A's ordered list of <a>descriptor-tokens</a> is
+              present at the beginning of B's ordered list of <a>descriptor-tokens</a>.
             </p>
             <aside class="example">
               <table class="data">