Engine: macro.run's description lists only what it returns here

`shifted` comes with the footprint in the pull request above; here a shift rule stops the run as
`fail` does, which the description now says.

crates/engine/src/cmd/macros.rs

@@ -11,7 +11,7 @@ pub fn specs() -> Vec<CommandSpec> {
         "Run Macro",
         [],
         None,
-        "{name, inputs?: {Input: \"B2:D9\"} | \"B2:D9\", onConflict?: ask|fail|overwrite|shiftDown|shiftRight, overwrite?: bool, approve?: bool, timeLimit?: seconds} runs as one undo step; any error rolls it all back → {macro, ran, inputs, stopped?, shifted?}",
+        "{name, inputs?: {Input: \"B2:D9\"} | \"B2:D9\", onConflict?: ask|fail|overwrite|shiftDown|shiftRight (a shift stops the run as fail does), overwrite?: bool, approve?: bool, timeLimit?: seconds} runs as one undo step; any error rolls it all back → {macro, ran, inputs, stopped?}",
         has_doc,
         run
     )]