Add a prelude and edit README.

Author: BGR360

README.md

@@ -2,4 +2,7 @@
 
 This is a library for tracking memory usage in [Bevy] apps.
 
-[Bevy]: https://lib.rs/bevy
+It is based on the [`datasize`] crate.
+
+[Bevy]: https://lib.rs/bevy
+[`datasize`]: https://lib.rs/datasize

src/lib.rs

@@ -15,3 +15,8 @@ pub use config::MemoryConfig;
 pub use plugin::MemoryUsagePlugin;
 pub use resource::MemoryUsage;
 pub use stats::MemoryStats;
+
+#[allow(missing_docs)]
+pub mod prelude {
+    pub use crate::{MemoryConfig, MemoryUsage, MemoryUsagePlugin, RegisterSizedTypes};
+}