multiboot2-common: doc improvement with figures

Author: phip1611

multiboot2-common/README.md

@@ -5,6 +5,23 @@
 
 Common helpers for the `multiboot2` and `multiboot2-header` crates.
 
+## Architecture
+
+The following figures, not displayable in `lib.rs` / on `docs.rs` unfortunately,
+outline the design of this crate:
+
+![Overview Multiboot2 Structures](./overview-multiboot2-structures.drawio.png "Overview Multiboot2 Structures")
+
+Overview of Multiboot2 structures: Multiboot2 boot informations, boot
+information tags, Multiboot2 headers, and Multiboot2 header tags all share the
+same technical foundation: They have a common header and a possible dynamic
+size, depending on the header.
+
+![Crate Architecture Overview](./architecture.drawio.png "Crate Architecture Overview")
+
+Overview of how raw bytes are modelled to be representable by high-level rusty
+types.
+
 ## MSRV
 
 The MSRV is 1.70.0 stable.