Changes planned-start date narrative

Ref: https://github.com/IATI/IATI-Extra-Documentation/issues/288
Changes country/region percentages

Ref: https://github.com/IATI/IATI-Extra-Documentation/issues/287
Edits code example for multiple countries

Ref: https://github.com/IATI/IATI-Extra-Documentation/issues/287
Edits code example for multiple regions

Ref: https://github.com/IATI/IATI-Extra-Documentation/issues/287
Merge pull request #289 from IATI/201-exampleXML-fixes

Edits 201 example XML and code examples