crane/gcrane: add pages (#13853)

pages/osx/gcrane-completion.md

@@ -0,0 +1,37 @@
+# gcrane completion
+
+> Generate the autocompletion script for gcrane for the specified shell.
+> The available shells are `bash`, `fish`, `powershell`, and `zsh`.
+> More information: <https://github.com/google/go-containerregistry/blob/main/cmd/gcrane/README.md>.
+
+- Generate the autocompletion script for your shell:
+
+`gcrane completion {{shell_name}}`
+
+- Disable completion descriptions:
+
+`grance completion {{shell_name}} --no-descriptions`
+
+- Load completions in your current shell session (bash/zsh):
+
+`source <(gcrane completion bash/zsh)>`
+
+- Load completions in your current shell session (fish):
+
+`gcrane completion fish | source`
+
+- Load completions for every new session (bash):
+
+`gcrane completion bash > $(brew --prefix)/etc/bash_completion.d/gcrane`
+
+- Load completions for every new session (zsh):
+
+`gcrane completion zsh > $(brew --prefix)/share/zsh/site-functions/_gcrane`
+
+- Load completions for every new session (fish):
+
+`gcrane completion fish > ~/.config/fish/completions/gcrane.fish`
+
+- Display help:
+
+`gcrane completion {{shell_name}} {{-h|--help}}`