Remove simd-kmeans as a default feature 'cause it's broken

Cargo.toml

@@ -16,7 +16,7 @@ rand = { version = "0.8.5", optional = true }
 kmeans = { version = "0.2.1", optional = true }
 
 [features]
-default = ["simd-kmeans"]
+#default = ["simd-kmeans"]
 # use the kmeans crate instead of the internal kmeans implementation. the crate
 # is faster and uses SIMD but requries nightly Rust.
 simd-kmeans = ["kmeans"]