Supporting auto complete and a build-release script

README.md

@@ -290,6 +290,31 @@ constructor injection -- the simplest form of dependency inversion.
 | `anvil board --remove NAME` | Remove a board profile |
 | `anvil board --default NAME` | Set the default board |
 | `anvil refresh [--force] [--file P] [--ignore P] [--unignore P]` | Update project infrastructure |
+| `anvil completions SHELL` | Generate tab-completion script (bash, zsh, fish, powershell) |
+
+---
+
+## Tab Completion
+
+Anvil can generate shell completion scripts so that pressing Tab completes
+commands, flags, and arguments:
+
+```bash
+# Bash (add to ~/.bashrc)
+eval "$(anvil completions bash)"
+
+# Zsh (add to ~/.zshrc)
+eval "$(anvil completions zsh)"
+
+# Fish
+anvil completions fish > ~/.config/fish/completions/anvil.fish
+
+# PowerShell (add to $PROFILE)
+anvil completions powershell | Out-String | Invoke-Expression
+```
+
+After setup, `anvil ref<Tab>` completes to `anvil refresh`, and
+`anvil pin --<Tab>` shows all available flags.
 
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