Eurosignal: Add ROM description for E300 pagers

docs/eurosignal.html

@@ -260,6 +260,19 @@ Learn how to build your own ROM from a few diodes:
 </a>
 </p>
 
+<p>
+<a href="eurosignal_e300.txt">
+<ul>
+<li>SEL E300</li>
+<li>Motorola E300 M</li>
+<li>Compur E300 ES</li>
+<li>SEL E300-1</li>
+<li>Motorola E300-1 M</li>
+<li>Compur E300-1 ES</li>
+</ul>
+</a>
+</p>
+
 <p>
 <a href="eurosignal_fu20.txt">
 <ul>