update-manifest.xml

<?xml version="1.0" encoding="utf-8"?>
<updates>
    <update>
        <name>NPEU: plg_ckeditor</name>
        <description>Joomla! plg_ckeditor plugin</description>
        <element>ckeditor</element>
        <type>plugin</type>
        <folder>editors</folder>
        <version>4.1.1</version>
        <client>site</client>
        <infourl title="NPEU: plg_ckeditor">https://github.com/NPEU/plg_ckeditor/releases/tag/v4.1.1</infourl>
        <downloads>
            <downloadurl type="full" format="zip">https://github.com/NPEU/plg_ckeditor/archive/v4.1.1.zip</downloadurl>
        </downloads>
        <targetplatform name="joomla" />
        <tags>
            <tag>stable</tag>
        </tags>
    </update>
</updates>