feat: implement UUID v6, v7 and v8 fake value generation

[LNSD]

This pull request includes several updates, improving documentation, adding new features, and enhancing UUID generation. The most significant changes involve updating documentation for various modules, supporting new UUID versions, and enhancing feature flag descriptions.

Documentation Improvements:

• Enhanced feature flag descriptions in fake/src/lib.rs to include new integrations and provide clearer explanations.

UUID Enhancements:

• Added support for UUID versions 6, 7, and 8 in fake/src/impls/uuid/mod.rs, including new structs and Dummy trait implementations for each version. [1] [2]

Feature Flag and Configuration Updates:

• Enabled doc_cfg feature for docs.rs to improve documentation visibility for feature-gated items.
• Added cfg_attr annotations to conditionally compile documentation for feature-gated items in fake/src/lib.rs. [1] [2] [3]

Dependency Updates:

• Updated uuid dependency to include additional features for new UUID versions in fake/Cargo.toml.

[LNSD]

@cksac Thank you so much for your incredible work on this project! I appreciate all the effort put in to keep everything running. Keep up the great work! 🙏🏼

[LNSD]

The Clippy CI check is failing due to an issue unrelated to this PR's changes: https://github.com/cksac/fake-rs/actions/runs/12311626538/job/34406609218?pr=207#step:5:75

error: elided lifetime has a name
Error:    --> fake/src/faker/mod.rs:25:72
    |
25  |               pub fn $name$(< $($lts),* >)?($($arg:$typ),*) -> raw::$name<$locale_s> {
    |                                                                          ^ this elided lifetime gets resolved as `'a`
...
204 | /     def_fakers! {
205 | |         Digit();
206 | |         NumberWithFormat<'a>(fmt: &'a str);
    | |                          -- lifetime `'a` declared here
207 | |     }
    | |_____- in this macro invocation
    |
    = note: `-D elided-named-lifetimes` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(elided_named_lifetimes)]`
    = note: this error originates in the macro `def_fakers` (in Nightly builds, run with -Z macro-backtrace for more info)