Remove normative text in informative section.

index.html

@@ -311,9 +311,9 @@ <h2>Introduction</h2>
       <p>
 A [=controller document=] is a set of data that specifies one or more
 relationships between a [=controller=] and a set of data, such as a set of
-public cryptographic keys. The [=controller document=] SHOULD
-contain [=verification relationships=] that explicitly permit the use of
-certain [=verification methods=] for specific purposes.
+public cryptographic keys. The [=controller document=] contains [=verification
+relationships=] that explicitly permit the use of certain [=verification
+methods=] for specific purposes.
       </p>
       <p>
 It is expected that other specifications, such as [[[?DID-CORE]]], will profile