ZCML File
browser.zcml

<configure
    xmlns="http://namespaces.zope.org/zope"
    xmlns:browser="http://namespaces.zope.org/browser"
    >
<browser:defaultView
    name="index.html"
    />
<browser:defaultSkin
    name="Rotterdam"
    />
<include
    package="zope.app.exception.browser"
    />
<include
    package="zope.traversing.browser"
    />
<include
    package="zope.app.security.browser"
    />
<include
    package="zope.app.container.browser"
    />
<include
    package="zope.app.form.browser"
    />
<include
    package="zope.app.component.browser"
    />
</configure>