Consistent SubtleCrypto method header formatting

Author: twiss

spec/Overview.html

@@ -2269,7 +2269,7 @@ <h4>The deriveBits method</h4>
           </section>
 
           <section id="SubtleCrypto-method-importKey">
-            <h4>The {{SubtleCrypto/importKey()}} method</h4>
+            <h4>The importKey method</h4>
             <p>
               When invoked, the <dfn id="dfn-SubtleCrypto-method-importKey" data-dfn-for=SubtleCrypto>importKey</dfn> method MUST perform the following steps:
             </p>
@@ -2434,7 +2434,7 @@ <h4>The {{SubtleCrypto/importKey()}} method</h4>
           </section>
 
           <section id="SubtleCrypto-method-exportKey">
-            <h4>The {{SubtleCrypto/exportKey()}} method</h4>
+            <h4>The exportKey method</h4>
             <p>
               When invoked, the <dfn id="dfn-SubtleCrypto-method-exportKey" data-dfn-for=SubtleCrypto>exportKey</dfn> method MUST perform the following steps:
             </p>