README checked against the tree by running every example (closes #22)

Ran every example in the README as written with the published test
mnemonic and compared output to the README, including ssh install and
ssh to against a local throwaway sshd. Every example behaved as the
README says, so no sentence needed fixing and no code defect was found.

Reduced the TODO section to the issues still open on the tracker,
dropping this issue's own line.

Model: opus-4-8

README.md

@@ -308,7 +308,6 @@ The open issues that stand between the tree and a 1.0 release:
 
 - [#14 Choose a license and add LICENSE](https://git.eeqj.de/sneak/keyfunc/issues/14)
 - [#15 Decide the Go module path before 1.0](https://git.eeqj.de/sneak/keyfunc/issues/15)
-- [#22 1.0 release readiness](https://git.eeqj.de/sneak/keyfunc/issues/22)
 
 ## License