code: def run(self):
          
          document = self.state.document
          env = document.settings.env
          buildpath = env.app.outdir
          link = self.arguments[0]
  
          try:
              r = requests.get(link)
              r.raise_for_status()
              downloadpath = os.path.join(buildpath, '_downloads')
              if not os.path.isdir(downloadpath):
                  os.makedirs(downloadpath)
              rstfile = os.path.join(downloadpath, os.path.basename(link))
              with open(rstfile, 'w') as f:
                  f.write(r.text)
              rstfile = os.path.relpath(rstfile, os.path.dirname(env.doc2path
                                                                 (env.docname)))
              self.arguments = [rstfile]
              return super(RemoteInclude, self).run()
          except Exception:
              err = 'Unable to resolve ' + link
              return [document.reporter.warning(str(err), line=self.lineno)]
docs: Return rel path to a downloaded file as `include` node argument.