chore: vendor nucleo-ext + fork, so we can depend on our changes properly (#3284)

We cannot publish to crates.io without specifying a version, and we
cannot do that without properly forking nucleo. We're shipping
atuin-nucleo, but will likely drop this if we can get our changes
upstream. This is highlighted in the README + manifest, and the original
author is still included.

Originally forked here: https://github.com/atuinsh/nucleo-ext

cc @BinaryMuse - this should just be a vendor + restructure, but would
appreciate the sanity check

## Checks
- [ ] I am happy for maintainers to push small adjustments to this PR,
to speed up the review cycle
- [ ] I have checked that there are no existing pull requests for the
same thing

1 files changed, 19 insertions, 0 deletions

diff --git a/crates/atuin-nucleo/matcher/Cargo.toml b/crates/atuin-nucleo/matcher/Cargo.toml
new file mode 100644
index 00000000..feb10310
--- /dev/null
+++ b/crates/atuin-nucleo/matcher/Cargo.toml
@@ -0,0 +1,19 @@
+[package]
+name = "atuin-nucleo-matcher"
+description = "plug and play high performance fuzzy matcher"
+authors = ["Pascal Kuthe <pascalkuthe@pm.me>"]
+version = "0.3.1"
+edition = "2021"
+license = "MPL-2.0"
+repository = "https://github.com/atuinsh/atuin"
+readme = "../README.md"
+
+[dependencies]
+memchr = "2.5.0"
+unicode-segmentation = { version  = "1.10", optional = true }
+
+[features]
+default = ["unicode-normalization", "unicode-casefold", "unicode-segmentation"]
+unicode-normalization = []
+unicode-casefold = []
+unicode-segmentation = ["dep:unicode-segmentation"]