Document Weblogic deployment

[philwebb]

Weblogic deployment works buy you have to jump though a couple of hoops. We should document that:

1. You need to extends SpringBootServletInitializer AND implement WebApplicationInitializer directly

2. You need to add a WEB-INF/weblogic.xml to favor bundled SLF4J:

<?xml version="1.0" encoding="UTF-8"?>
<wls:weblogic-web-app
    xmlns:wls="http://xmlns.oracle.com/weblogic/weblogic-web-app"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/ejb-jar_3_0.xsd http://xmlns.oracle.com/weblogic/weblogic-web-app http://xmlns.oracle.com/weblogic/weblogic-web-app/1.4/weblogic-web-app.xsd">
    <wls:container-descriptor>
        <wls:prefer-application-packages>
            <wls:package-name>org.slf4j</wls:package-name>
        </wls:prefer-application-packages>
    </wls:container-descriptor>
</wls:weblogic-web-app>