Replace placeholders with data in a template DOCX

In this sample we load a template DOCX (ProcurementLetterTpl.docx) into an instance of GcWordDocument. The source document is a letter template, with placeholder strings in place of variable data (addressee's name, address etc.). We then replace placeholders with sample data, using the RangeBase.Replace extension method. The modified document filled with actual data is then returned.