docs: deploy using dagger

Signed-off-by: Andrea Luzzardi <aluzzardi@gmail.com>

stdlib/dagger/op/op.cue

@@ -40,6 +40,11 @@ package op
 	dir: string
 }
 
+#Workdir: {
+	do:   "workdir"
+	path: string
+}
+
 #Exec: {
 	do: "exec"
 	args: [...string]

stdlib/dagger/op/op_fullop.cue

@@ -12,6 +12,7 @@ package op
 	#Copy |
 	#Load |
 	#Subdir |
+	#Workdir |
 	#WriteFile |
 	#Mkdir |
 	#DockerBuild) & {do: string}