Will download HTML of URL provided at runtime, will also parse html extract embedded links and download associated html.
- requests library used to GET HTML and parse embeded links
- Will normalise a url by removing and non alphanumeric chars and replace with _ also remove http:// eg. https://python.org/ => python_org_
- Save main url and embeded urls as .html and produce lookup.json to reconstruct urls from normalised filenames.