[#22] Starts to add the IATI registration agancy to the list

Still needs a description and a URL
Merge branch 'master' of github.com:IATI/IATI-Codelists-NonEmbedded into 22-add-XI-IATI
[#22] Adds the rest of the information required for XI-IATI
Merge pull request #31 from IATI/22-add-XI-IATI

22 add XI-IATI