code: def _show_documentation(self):
          documents = []
          for key, document in self.app.documents.get().items():
              if key != "main":
                  documents.append((key, document))
          documents = sorted(documents, key=lambda x: x[0])
          main = self.app.documents.get("main")
          if main is not None:
              documents.insert(0, (main.name, main))
          user_answer = ""
          index = 0
          while user_answer != "X":
              if index < 0:
                  index = 0
              if index > len(documents) - 1:
                  index = len(documents) - 1
              document = documents[index][1]
              os.system('cls' if os.name == 'nt' else 'clear')
              echo(Environment().from_string(document.content).render(app=self.app, plugin=document.plugin))
              source = "This document is registered by '%s' under the name '%s'" % (document.plugin.name, document.name)
              echo("-" * len(source))
              echo(source)
              echo("-" * len(source))
              commands = "Actions: "
              if index < len(documents) - 1:
                  commands += "[N]ext, "
              if index > 0:
                  commands += "[P]revious, "
              commands += "E[x]it"
              echo(commands)
              if index < len(documents) - 1:
                  default = "N"
              elif index > 0:
                  default = "P"
              else:
                  default = "X"
              user_answer = prompt("Select your action", default=default).upper()
              if user_answer == "N":
                  index += 1
              elif user_answer == "P":
                  index -= 1