Enable shell completion for configured command aliases

README.md

@@ -169,6 +169,14 @@ it for new shells. The command alias takes priority over a host alias with the
 same name and works even when no servers are cached. Environment override:
 `NETSSH_SHELL_ALIAS=j`.
 
+The command alias also supports shell completion: `j ser<Tab>` suggests cached
+server names, just like `netssh ser<Tab>`. The wizard, shell hook, installer, and
+`netssh completion install` maintain the alias completion files automatically.
+Changing or disabling the alias removes its old generated completion files.
+Bash requires bash-completion to load user completion files; for Zsh, include
+`~/.zfunc` in `fpath` before running `compinit` as described below. Fish loads
+completion files automatically. Open a new terminal after changing the alias.
+
 ### API tokens
 
 NetBox supports two token formats: