chore: Move index related things to the meilidb-core workspace member

meilidb-core/src/data/mod.rs

@@ -0,0 +1,16 @@
+mod doc_ids;
+mod doc_indexes;
+mod shared_data;
+
+use std::slice::from_raw_parts;
+use std::mem::size_of;
+
+pub use self::doc_ids::DocIds;
+pub use self::doc_indexes::{DocIndexes, DocIndexesBuilder};
+pub use self::shared_data::SharedData;
+
+unsafe fn into_u8_slice<T: Sized>(slice: &[T]) -> &[u8] {
+    let ptr = slice.as_ptr() as *const u8;
+    let len = slice.len() * size_of::<T>();
+    from_raw_parts(ptr, len)
+}