docs: document SSH options, uninstall, and zsh completion for v0.0.21

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

CHANGELOG.md

@@ -1,5 +1,18 @@
 # Changelog
 
+## v0.0.21
+
+- Ship a zsh completion script built for large caches: 5000 hosts complete in under 0.1 s instead of hanging for seconds with Cobra's generated script.
+- Add `completion.max_results` to limit the number of hostnames offered per completion.
+- Register zsh completion in the managed `.zshrc` block (`fpath` and `compdef`), also when `compinit` already ran, e.g. with oh-my-zsh. The installer reports which completions it set up.
+- Add `netssh uninstall [--keep-config] [--dry-run] [--yes]` to remove the binary, profile entries of all versions, completions, cache, and config (with a private backup).
+- Write marked `# >>> netssh >>>` blocks from `netssh hook install` and the wizard, replacing unmarked entries of older versions instead of appending.
+- Add jump host support: `ssh.proxy_jump` globally, per NetBox instance, and per rule, plus `--jump HOST` and `--no-jump`.
+- Add `ssh.host_key_checking` (`strict`, `accept-new`, `off`) for netssh connections only.
+- Add `ssh.target: name|hostname` so `~/.ssh/config` host patterns apply and known_hosts entries belong to the device, and `ssh.address_family`.
+- Add `ssh.options` and `ssh.extra_args`, and `ssh.rules` that match by tag, instance, kind, or name pattern.
+- Add `netssh --version` / `netssh version` and `netssh --dry-run` to print the final ssh command.
+
 ## v0.0.20
 
 - Configure multiple named NetBox instances and search them together in parallel.