chore: address final comments

docs/mapstore.md

@@ -0,0 +1,41 @@
+# MapStore
+
+<!-- toc -->
+
+- [Implementations](#implementations)
+  * [SimpleMap](#simplemap)
+  * [BadgerV4](#badgerv4)
+
+<!-- tocstop -->
+
+The `MapStore` is a simple interface used by the SM(S)T to store, delete and
+retrieve key-value pairs. It is intentionally simple and minimalistic so as to
+enable different key-value engines to implement and back the trie database.
+
+See: [the interface](../kvstore/interfaces.go) for a more detailed description
+of the simple interface required by the SM(S)T.
+
+## Implementations
+
+### SimpleMap
+
+`simplemap` is a simple kv-store shipped with the SM(S)T. The SMT library that
+can be used without it as long as the selected node store adheres to the
+`Mapstore` interface.
+
+This library is recommended for development, testing and exploration purposes.
+
+This library **SHOULD NOT** be used in production.
+
+See [simplemap.go](../kvstore/simplemap/simplemap.go) for more details.
+
+### BadgerV4
+
+This library provides a wrapper around [dgraph-io/badger][badgerv4] to adhere
+to the `MapStore` interface. See the [full documentation](./badger-store.md)
+for additional functionality and implementation details.
+
+See: [badger](../kvstore/badger/) for more details on the implementation of
+this submodule.
+
+[badgerv4]: https://github.com/dgraph-io/badger

docs/smt.md

@@ -472,7 +472,7 @@ the [`kvstore`](../kvstore/) directory.
 This library defines the `SimpleMap` interface which is implemented as an
 extremely simple in-memory key-value store.
 
-Although it is is a submodule, it is ideal for simple, testing or non-production
+Although it is a submodule, it is ideal for simple, testing or non-production
 use cases. It is used in the tests throughout the library.
 
 See [simplemap.go](../kvstore/simplemap/simplemap.go) for the implementation