use one version number and add 10 as supported version

docs/developer.rst

@@ -55,11 +55,12 @@ A minimum valid **info.xml** would look like this:
           xsi:noNamespaceSchemaLocation="https://apps.nextcloud.com/schema/apps/info.xsd">
         <id>news</id>
         <name>News</name>
+        <summary>An RSS/Atom feed reader</summary>
         <description>An RSS/Atom feed reader</description>
-        <author>Bernhard Posselt</author>
-        <category>multimedia</category>
         <version>8.8.2</version>
         <licence>agpl</licence>
+        <author>Bernhard Posselt</author>
+        <category>multimedia</category>
         <dependencies>
             <!-- owncloud tag is required on Nextcloud 9, 10 and 11 -->
             <owncloud min-version="9.1"/>

nextcloudappstore/core/api/v1/release/info.xsd

@@ -335,6 +335,8 @@
                         maxOccurs="unbounded"/>
             <xs:element name="lib" type="min-max-version" minOccurs="0"
                         maxOccurs="unbounded"/>
+            <xs:element name="owncloud" type="nextcloud" minOccurs="1"
+                        maxOccurs="1"/>
             <xs:element name="nextcloud" type="nextcloud" minOccurs="1"
                         maxOccurs="1"/>
         </xs:sequence>

nextcloudappstore/core/api/v1/release/pre-info.xslt

@@ -72,6 +72,7 @@
             <xsl:copy-of select="database"/>
             <xsl:copy-of select="command"/>
             <xsl:copy-of select="lib"/>
+            <xsl:copy-of select="owncloud"/>
             <xsl:copy-of select="nextcloud"/>
             <xsl:if test="not(nextcloud)">
                 <xsl:variable name="min" select="owncloud/@min-version[.='9.0' or '9.1' or '9.2']"/>