Valid on this line and  any any other `Warning` / `Error` (`SourceAnnotation`) construction: 

I would love this warnings / error to have the source maps associated with it (e.g. where it was located in the source blueprint file). Without it you can't reliably highlight the line in the blueprint editor. 

I suggest to add a parameter to URITemplateParser::parse(const URITemplate uri, ParsedURITemplate& result) of type `SourceCharactersBlock` and use it when constructing warnings / errors. The map would ideally include just the URI Template position in the source but it is OK if it is equal to the complete Resource Markdown header.