Add link to dev builds to README.md

Took 1 minute

Author: DerFrZocker

README.md

@@ -5,6 +5,7 @@ Links
 -----
 * [Spigot plugin page](https://www.spigotmc.org/resources/64339/) (English)
 * [Minecraft-server.eu plugin page](https://minecraft-server.eu/forum/resources/24/) (German)
+* [Dev Builds](https://jenkins.derfrzocker.de/job/Custom-Ore-Generator-Dev/)
 * [Discord](http://discord.derfrzocker.de)
 * [Wiki](https://github.com/DerFrZocker/Custom-Ore-Generator/wiki)
 * [bStats](https://bstats.org/plugin/bukkit/Custom-Ore-Generator)