apply some Vercel suggestions

src/pages/cw-storage-plus/containers/item.mdx

@@ -4,7 +4,12 @@ An `Item` is a container that stores a single value under a specific key in
 storage.
 
 Merely constructing the `Item` object does not commit anything to storage. If an
-`Item` has never been written to before, it will be empty.
+`Item` has never been written to before (or the value has been
+[removed](https://docs.rs/cw-storage-plus/latest/cw_storage_plus/struct.Item.html#method.remove)),
+it will be empty.
+
+Under the hood, values are serialized with [`serde`](https://serde.rs/) and
+[`serde_json_wasm`](https://docs.rs/serde_json_wasm/).
 
 Use `save` to write to an `Item`.
 

src/pages/cw-storage-plus/containers/map.mdx

@@ -14,6 +14,10 @@ trait. Most commonly, the key is simply a `String` or
 Other types include binary strings (`Vec<u8>`, `[u8; N]`, `&[u8]`), numerical
 types, or even tuples, which can be used to create composite keys.
 
+<Callout>
+Unlike values, keys do **not** need to implement anything like `serde::Serialize` or `serde::Deserialize`. Key encoding is handled by the `PrimaryKey` trait.
+</Callout>
+
 ## Values
 
 The values, as usual, are serialized as JSON and must implement the
@@ -140,14 +144,13 @@ assert_eq!(alices_balances, vec![("osmo".to_string(), 200), ("uusd".to_string(),
 
 <Callout type="warning">
 
-As seen here, the order of keys isn't always lexicographic. If you need things
-ordered, the safe thing to do is to collect them in a vector and `sort` it.
+As seen here, the order of keys isn't always lexicographic.
 
-If you'd rather avoid that, here's how things work: under the hood, every
-component of a composite key is length-prefixed except for the last one. If
-you're only iterating over the last component, you can expect things to be
-ordered lexicographically. For non-final components, shorter strings will always
-come before longer ones.
+If you need to rely on iteration order in maps with composite keys, here's how
+things work: under the hood, every component of a composite key is
+length-prefixed except for the last one. If you're only iterating over the last
+component, you can expect things to be ordered lexicographically. For non-final
+components, shorter strings will always come before longer ones.
 
 In the example, note how `"bob"` (a non-last component) comes before `"alice"`.
 Also note how once we lock the first component to `"alice"`, entries are ordered