Documentation: Reference road stops from main NewGRF pages

docs/newgrf-additions-nml.html

@@ -26,6 +26,11 @@
 
 	<p>All of the non-standard variables listed below will return 0 on OpenTTD versions which do not support these features/variables, including standard trunk OpenTTD and older/other patchpack versions.</p>
 
+	<h3>Features with separate pages</h3>
+	<ul>
+	<li><a href="newgrf-roadstops-nml.html">Road stops (FEAT_ROADSTOPS)</a></li>
+	</ul>
+
 	<h3><a href="https://newgrf-specs.tt-wiki.net/wiki/NML:Builtin_functions">Builtin functions</a></h3>
 
 	<p>

docs/newgrf-additions.html

@@ -24,6 +24,11 @@
 	<p>A subset of the features listed below are also supported in a fork of NML, see the associated <a href="newgrf-additions-nml.html">NML document</a> for more details.</p>
 	<p>NewGRFs which use any of these features SHOULD use the <a href="#feature-test">feature testing</a> mechanism described below to check whether individual added features are supported.</p>
 
+	<h3 id="separate_features">Features with separate pages</h3>
+	<ul>
+	<li><a href="newgrf-roadstops.html">Road stops</a></li>
+	</ul>
+
 	<h3 id="feature-test">Action 14 - Feature Tests</h3>
 	<p>See <a href="https://newgrf-specs.tt-wiki.net/wiki/Action14">Action 14 Specification</a> for background information.</p>
 	<h4 id="FTST">Feature Test: C "FTST"</h4>