1.1 (20230313)

- Replace original June 1991 GPLv2 with February 1999 (post-LGPLv2.1) GPLv2
- Fix mbox From_ header parsing (handle single-letter as an email address substitute) (spotted by github/traut21)
- Add CODE_OF_CONDUCT.md
- Add LICENSES/* and .reuse/dep5 (REUSE 3.0 compliant)
- Add references to the codeberg repository