docs: Update for EGL environment variables.
Mention that EGL_DRIVER should be a full path, and add a link from
envvars.html to egl.html.
diff --git a/docs/envvars.html b/docs/envvars.html
index bb1c914..fd1700a 100644
--- a/docs/envvars.html
+++ b/docs/envvars.html
@@ -69,6 +69,10 @@
<li>R300_NO_TCL - if set, disable hardware-accelerated Transform/Clip/Lighting.
</ul>
+<p>
+Mesa EGL supports different sets of environment variables. See the
+<a href="egl.html">Mesa EGL</a> page for the details.
+</p>
</BODY>
</HTML>