Feature request: Sort lints tables

[taladar]

Recently cargo added the ability to specify lints in Cargo.toml. Those seem like good candidates to add to the list of tables to sort.

[getong]

Cargo.toml

[lints]
rust.unexpected_cfgs = { level = "warn", check-cfg = ['cfg(wasm_bindgen_unstable_test_coverage)'] }

error msg:

thread 'main' panicked at /Users/a/.cargo/registry/src/rsproxy.cn-0dccff568467c15b/cargo-sort-1.0.9/src/sort.rs:113:46:
called `Result::unwrap()` on an `Err` value: TomlError { message: "TOML parse error at line 37, column 5\n   |\n37 | rust.unexpected_cfgs = { level = \"warn\", check-cfg = ['cfg(wasm_bindgen_unstable_test_coverage)'] }\n   |     ^\nUnexpected `.`\nExpected `=`\n" }
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace