Log Message:
spleen: update to 2.0.1.

Spleen 2.0.1 (2023-11-17)

- Add a 'com' target to generate SPLEEN.COM, the DOS version of Spleen
- Also add 'com' in the 'all' target
- Update README to add a link to the Guix package
- In the Spleen loader for DOS, put 4C00h in ax and not 4Ch
- README.md: add Gentoo package link
- Switch to using Oxipng as it compresses even more than OptiPNG
- Add a new FAQ file answering frequently asked questions about Spleen
- Remove C0 control characters range in the 8x16, 16x32, and 32x64 versions