freedesktop.org.xml does not contain an entry for a Java Network Launch Protocol
file (.jnlp).

The proposed xml entry follows:

<?xml version="1.0" encoding="UTF-8"?>
<mime-info xmlns="http://www.freedesktop.org/standards/shared-mime-info">
  <mime-type type="application/x-java-jnlp-file">
    <sub-class-of type="text/xml"/>
    <comment>Java Network Launched Application</comment>
    <glob pattern="*.jnlp"/>
    <magic priority="85">
      <match type="string" value="&lt;jnlp" offset="0:64"/>
    </magic>
  </mime-type>
</mime-info>

The priority is set above normal so that this isn't recognized as a normal
text file.