minor typos, names and code formatting changes
Add new functionality to TODO list
Change a way of creating testing file, now in each folder are created all kind of test files
Integration of Rename class and Renpyable. All renaming logic from functions correct_tiff_names and correct_numbers was moved to Rename class and unit tested
Deleted correct_pdf_file_names because class Rename corrects names for every file extension. File must be in proper folder in this case in folder TIFF_DIRECTORY
 minor typos correction