separate week 1 solution

Signed-off-by: Alex Chi Z <iskyzh@gmail.com>

mini-lsm-week-1/src/lib.rs

@@ -0,0 +1,9 @@
+pub mod block;
+pub mod iterators;
+pub mod lsm_iterator;
+pub mod lsm_storage;
+pub mod mem_table;
+pub mod table;
+
+#[cfg(test)]
+mod tests;