Replace doc code

In the ReStructuredText (*.txt) files, many of the copies of Python code were out of date. Replaced copies of Python code with links to sections of the corresponding files. This dramatically reduced the number of lines of code to maintain. This will help keep documentation in sync with code (but will not guarantee synchronization). Renamed two ReStructuredText files to match corresponding Python files. Modified code files for improved readability. Modified .gitignore to ignore tmp directories.
That indentation was on purpose, to distinguish the lines introducing a parameters from the lines with the description. Maybe there is a better way of presenting that, but those different blocks (one for each variable) should stay visually separated.