FilterType: Add examples and timings to docs

[dbrgn]

Preview:

Unfortunately Rustdoc does not provide a simple method to include images in the docs (see rust-lang/rust#32104). I quickly considered including them as inline base64, but that would add a huge amount of text to the enum documentation. Instead, I linked to them from GitHub.

This means that when doing local changes, these need to be previewed by manually replacing the github URL with a relative link (../../../docs/). However, it should work on docs.rs.

I license past and future contributions under the dual MIT/Apache-2.0 license,
allowing licensees to chose either at their option.

[HeroicKatora]

If I understand the changes then these images would be included in the distributed crate. This will bloat it quite a bit, from ~150 kB to roughly 5 times that amount. You do seem think that is worth the documentation clarity. That doesn't seem as obvious to me, so maybe you can tell me why? Are there alternatives that could avoid that downside?

[dbrgn]

Ah, I think you're right that the docs directory is being included in the crate. I wasn't aware of that. We could move the pictures into the examples directory, which is excluded in Cargo.toml.

[HeroicKatora]

Triage: It seems clear how to address the requested changes. Is there some hold-up?

[dbrgn]

@HeroicKatora fixed!

[HeroicKatora]

Thank you :)