Extract browser.RemoveUserContextParameters type (#671)

Author: sadym-chromium

index.bs

@@ -2153,10 +2153,12 @@ user context and all browsing contexts in it without running
       <pre class="cddl remote-cddl">
       browser.RemoveUserContext = (
         method: "browser.removeUserContext",
-        params: {
-          userContext: browser.UserContext
-        },
+        params: browser.RemoveUserContextParameters
       )
+
+      browser.RemoveUserContextParameters = {
+        userContext: browser.UserContext
+      }
       </pre>
    </dd>
    <dt>Return Type</dt>