Create EJ2DataManager.md (#152)
Create EJ2DataManager.md (#152)

- Added EJ2DataManager in libraries
ralfhandl/odataorg.github.io,ODataOrg/odataorg.github.io,OData/odataorg.github.io,ralfhandl/odataorg.github.io,ODataOrg/odataorg.github.io,OData/odataorg.github.io