Support for BLEACH_ALLOWED_STYLES and BLEACH_ALLOWED_PROTOCOLS

[Arushi2012]

@marksweb Is there any plan to support these?

[marksweb]

@Arushi2012 From what I recall of the nh3 docs, these settings don't seem to match up to NH3

[blag]

Allowed protocols should be supported by NH3's url_schemes option now.

However, since neither the (Rust) Ammonia project or the (Python) NH3 project supports an allowlist for styles this project does not either.

I have added support for url_schemes in PR #54. We will have to wait for the Ammonia project and then the NH3 project to support style allowlists.

[blag]

PR #54 was subsumed by PR #57, which was merged. So we now support specifying url_schemes - this is partially done.

Still awaiting the Ammonia project and subsequently Python's NH3 project to implement an allowlist for styles.