Add prerender security/privacy considerations that link to other specs (

#321)

This gets started with security and privacy considerations for
prerendering by linking to existing considerations for the specs this
integrates with.

Note that considerations specific to prerendering still need to be
added.

prefetch.bs

@@ -776,6 +776,10 @@ The following parameters are defined for the "`prefetch`" token:
 
 See <a href="speculation-rules.html#security-considerations">Security considerations (Speculation Rules)</a>.
 
+For the integration of this spec with No-Vary-Search, see <a href="no-vary-search.html#security-considerations">No-Vary-Search Security considerations</a>.
+
 <h2 id="privacy-considerations">Privacy considerations</h2>
 
 See <a href="speculation-rules.html#privacy-considerations">Privacy considerations (Speculation Rules)</a>.
+
+For the integration of this spec with No-Vary-Search, see <a href="no-vary-search.html#privacy-considerations">No-Vary-Search Privacy considerations</a>.

prerendering.bs

@@ -1026,3 +1026,19 @@ APIs that require the "<code>visible</code>" [=Document/visibility state=]:
 
 More complicated cases:
 - [=Request Picture-in-Picture=] as invoked due to {{HTMLVideoElement/requestPictureInPicture()|video.requestPictureInPicture()}} requires either [=transient activation=], or the [=Document/visibility state=] to have been "<code>visible</code>". [[PICTURE-IN-PICTURE]]
+
+<h2 id="security-considerations">Security considerations</h2>
+
+See <a href="speculation-rules.html#security-considerations">Security considerations (Speculation Rules)</a>.
+
+For the integration of this spec with No-Vary-Search, see <a href="no-vary-search.html#security-considerations">No-Vary-Search Security considerations</a>.
+
+<p class="issue">Add security considerations that are specific to prerendering. See <a href="https://github.com/WICG/nav-speculation/issues/319">issue #319</a>.</p>
+
+<h2 id="privacy-considerations">Privacy considerations</h2>
+
+See <a href="speculation-rules.html#privacy-considerations">Privacy considerations (Speculation Rules)</a>.
+
+For the integration of this spec with No-Vary-Search, see <a href="no-vary-search.html#privacy-considerations">No-Vary-Search Privacy considerations</a>.
+
+<p class="issue">Add privacy considerations that are specific to prerendering. See <a href="https://github.com/WICG/nav-speculation/issues/319">issue #319</a>.</p>