docs: de-dup README (keep .adoc, port sponsor badge) (#25)

Family-wide doc de-dup that landed across the -iser repos during base
camp but was missed here (this repo was squash-merged before the
cleanup).

- Remove stale `README.md` (`README.adoc` is canonical), porting the
GitHub sponsor badge into `README.adoc`.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

https://claude.ai/code/session_01Mbq6yKF9RhFai6EQ7WqKhQ

---
_Generated by [Claude
Code](https://claude.ai/code/session_01Mbq6yKF9RhFai6EQ7WqKhQ)_

Co-authored-by: Claude <noreply@anthropic.com>

Author: hyperpolymath

README.adoc

@@ -6,6 +6,8 @@ Jonathan D.A. Jewell <j.d.a.jewell@open.ac.uk>
 :icons: font
 :source-highlighter: rouge
 
+image:https://img.shields.io/badge/Sponsor-%E2%9D%A4-pink?logo=github[Sponsor,link=https://github.com/sponsors/hyperpolymath]
+
 == What Is Affinescriptiser?
 
 Affinescriptiser takes existing code written in Rust, C, or Zig and wraps it with