Temporary files in modified TEMP path are not automatically deleted for html_file option

[MarkusEmmm]

' import Html2Image
temp_path = 'D:\temp\'
hti = Html2Image(output_path=path,
custom_flags=["--headless"],
temp_path=temp_path,
keep_temp_files=False)
hti.browser.use_new_headless = None

css = "body {background: white;}"

res = hti.screenshot(html_file=filename, css_str=css, save_as=name.replace('html','png'), size=size)'

While running above code I noticed that the temporary files do not get deleted in the designated location.
After I had issues with the system default TEMP driving increasing in size with large numbers of conversions, I switched to an alternate location.

I checked the method 'screenshot' and saw that temporary files only get deleted in the case of 'html_str' call.
However, for 'html_file' no such method was present. During the 'load_file' operation the original *.html got copied to the temp_path, but was never removed.

To fix I created a pull request.