More Clippy lint groups including pedantic

[allan2]

Five lints corrected:

• doc_markdown from pedantic (partial, see commit message)
• cast_lossless from pedantic
• use_self from nursery
• too_long_first_doc_paragraph from style
• cargo_common_metadata from cargo

Pedantic, nursery, and cargo group rules are added.

All lints are passing.

[WaffleLapkin]

cast_lossless and cargo_common_metadata fixes are a nice touch. everything else however doesn't look like an improvement to me.

[allan2]

I could remove the nursery group if maintainers prefer, as it is an experimental group.

use_self lint is still in nursery because of false positives, not for style reasons.

[allan2]

I've just kept the pedantic and cargo lint groups now. This is in line with rust-lang/cargo-bisect-rustc and rust-lang/rustc-perf.

[WaffleLapkin]

I did not change my opinions since #51 (review)