crane/gcrane: add pages (#13853)

pages/windows/gcrane-completion.md

@@ -0,0 +1,25 @@
+# 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 (powershell):
+
+`gcrane completion powershell | Out-String | Invoke-Expression`
+
+- Load completions for every new session (powershell):
+
+`Add above command to powershell profile`
+
+- Display help:
+
+`gcrane completion {{shell_name}} {{-h|--help}}`