I saw in a widget here, and maybe you can try create a folder inside your zip file with the entities. Following the architecture:
- MyExtension.zip
That is the example of the xml file that defines the data shape that I found:
<?xml version="1.0" encoding="UTF-8"?>
<Entities
build="b140"
majorVersion="8"
minorVersion="2"
modelPersistenceProviderPackage="PostgresPersistenceProviderPackage"
revision="1"
schemaVersion="1020"
universal="">
<DataShapes>
<DataShape
baseDataShape=""
description=""
documentationContent=""
homeMashup=""
lastModifiedDate="2018-03-20T14:54:13.211+02:00"
name="GanttChartData"
projectName=""
tags="Applications:GanttChart;Applications:Testing">
<avatar></avatar>
<DesignTimePermissions>
<Create></Create>
<Read></Read>
<Update></Update>
<Delete></Delete>
<Metadata></Metadata>
</DesignTimePermissions>
<RunTimePermissions></RunTimePermissions>
<VisibilityPermissions>
<Visibility></Visibility>
</VisibilityPermissions>
<ConfigurationTables></ConfigurationTables>
<FieldDefinitions>
<FieldDefinition
baseType="NUMBER"
description=""
name="duration"
ordinal="8"></FieldDefinition>
<FieldDefinition
baseType="DATETIME"
description=""
name="end"
ordinal="4"></FieldDefinition>
<FieldDefinition
baseType="STRING"
description=""
name="id"
ordinal="1"></FieldDefinition>
<FieldDefinition
baseType="STRING"
description=""
name="name"
ordinal="2"></FieldDefinition>
<FieldDefinition
baseType="NUMBER"
description=""
name="percentage"
ordinal="5"></FieldDefinition>
<FieldDefinition
baseType="STRING"
description=""
name="relationships"
ordinal="7"></FieldDefinition>
<FieldDefinition
baseType="STRING"
description=""
name="resource"
ordinal="6"></FieldDefinition>
<FieldDefinition
baseType="DATETIME"
description=""
name="start"
ordinal="3"></FieldDefinition>
</FieldDefinitions>
</DataShape>
</DataShapes>
</Entities>
Hope it works and help.