docs: def _generate_footer(notebook_object, notebook_type):
      """
      Internal function that is used for generation of the notebooks footer.
  
      ----------
      Parameters
      ----------
      notebook_object : notebook object
          Object of "notebook" class where the header will be created.
  
      notebook_type : str
          Notebook type: - "Main_Files_Signal_Samples"
                         - "Main_Files_By_Category"
                         - "Main_Files_By_Difficulty"
                         - "Main_Files_By_Tag"
                         - "Load"
                         - "Record"
                         - "Visualise"
                         - "Pre-Process"
                         - "Detect"
                         - "Extract"
                         - "Train_and_Classify"
                         - "Understand"
                         - "Evaluate"
  
      """
  
      footer_aux = FOOTER
      if "Main_Files" in notebook_type:
          footer_aux = footer_aux.replace("../MainFiles/", "")
  
      # ================ Insertion of the div reserved to the Notebook Description ===================
      notebook_object["cells"].append(nb.v4.new_markdown_cell(footer_aux,
                                                              **{"metadata":
                                                                 {"tags": ["footer"]}}))
  
      # ========== Code segment for application of the biosignalsnotebooks CSS style ===========
      notebook_object["cells"].append(nb.v4.new_markdown_cell(AUX_CODE_MESSAGE,
                                                              **{"metadata": {"tags": ["hide_mark"]}}))
      notebook_object["cells"].append(nb.v4.new_code_cell(CSS_STYLE_CODE,
                                                          **{"metadata": {"tags": ["hide_both"]}}))