Consider adding CSP support - nonce attr for inline style/script elements

It would be great when calling rendering functions to be able to use nonce value string, ie. keyword nonce=... - which value then get used as nonce attribute in and <style> tags in the rendered svg.

The embedding will be then feasible in website using more strict CSP policy.

Possibly the nonce attr. might be useful in the <svg> tag as well...

Start by locating pygal's rendering functions and the code that emits inline , <style>, and <svg> elements. Trace how rendering keyword arguments are handled, then verify that a supplied nonce is emitted on the requested elements and that existing rendering behavior remains unchanged.

Written by the indexing model from the issue text.