feat(docs): finish part 2

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

mini-lsm-starter/src/lsm_iterator.rs

@@ -1,9 +1,10 @@
 #![allow(unused_variables)] // TODO(you): remove this lint after implementing this mod
 #![allow(dead_code)] // TODO(you): remove this lint after implementing this mod
 
-use crate::iterators::impls::StorageIterator;
 use anyhow::Result;
 
+use crate::iterators::impls::StorageIterator;
+
 pub struct LsmIterator {}
 
 impl StorageIterator for LsmIterator {
@@ -24,7 +25,8 @@ impl StorageIterator for LsmIterator {
     }
 }
 
-/// A wrapper around existing iterator, will prevent users from calling `next` when the iterator is invalid.
+/// A wrapper around existing iterator, will prevent users from calling `next` when the iterator is
+/// invalid.
 pub struct FusedIterator<I: StorageIterator> {
     iter: I,
 }