Fix smart terms reference syntax

[ronaldtse]

Previously, Metanorma smart terms used the syntax of {{term, source}}, but it has flipped, and also became more complex for termbase references ({{<<termbase,clause>>,term}}).

This probably should be fixed in iev-data too.

So we need to flip them with this code.

    def swap_term_refs(string)
      string.gsub(/\{\{\s*([^\}]+)\s*,\s*([^\}]+)\s*\}\}/, '{{<<\2>>,\1}}')
    end

[ronaldtse]

This will also be handled by #6 .