[resize-observer] Add note about invocations from update the rendering loop in the html spec

Author: johannesodland

resize-observer-1/Overview.bs

@@ -395,6 +395,11 @@ Content rect for the <a>SVGGraphicsElement</a>s without CSS layout boxes is a re
 
 <h3 id="algorithms">Algorithms</h3>
 
+<p class="note">
+The following algorithms are invoked as a part of [=update the rendering=] in the html spec:
+<a>gather active resize observations at depth</a>, <a>has active resize observations</a>, <a>has skipped resize observations</a>, <a>broadcast active resize observations</a> and <a>deliver resize loop error notification</a>.
+</p>
+
 <h4 id="gather-active-observations-h">Gather active resize observations at depth</h4>
 
 It computes all active resize observations for a |document|. To <dfn export lt="gather active resize observations at depth | gather active resize observations">gather active resize observations at depth</dfn>, run these steps: