Add docker completions for zsh

chezmoi/dot_zshrc.d/executable_docker.zsh

@@ -0,0 +1,26 @@
+#!/usr/bin/zsh
+
+(
+	set -euo pipefail
+
+	if ! command -v docker &> /dev/null; then
+		exit 0
+	fi
+
+	zstyle ':completion:*:*:docker:*' option-stacking yes
+	zstyle ':completion:*:*:docker-*:*' option-stacking yes
+
+	DOCKER_COMPLETION_FILE="${ZSH_COMPLETIONS_DIR}/_docker"
+
+	if [ -r "$DOCKER_COMPLETION_FILE" ]; then
+		zstat -H COMPLETION_FILE_STAT "$DOCKER_COMPLETION_FILE"
+		zstat -H DOCKER_FILE_STAT "$(command -v docker)"
+
+		if [ "${COMPLETION_FILE_STAT[ctime]}" -ge "${DOCKER_FILE_STAT[ctime]}" ]; then
+			exit 0
+		fi
+	fi
+
+	curl -LSsf https://raw.githubusercontent.com/docker/cli/master/contrib/completion/zsh/_docker -o "$DOCKER_COMPLETION_FILE"
+	chmod +x "$DOCKER_COMPLETION_FILE"
+)