Update help text

src/hyperfine/app.rs

@@ -143,7 +143,9 @@ fn build_app() -> App<'static, 'static> {
  "Perform benchmark runs for each value in the comma-separated list VALUES. \
  Replaces the string '{VAR}' in each command by the current parameter value\
  .\n\nExample: hyperfine -L compiler gcc,clang '{compiler} -O2 main.cpp'\n\n\
- This performs benchmarks for 'gcc -O2 main.cpp' and 'clang -O2 main.cpp'.",
+ This performs benchmarks for 'gcc -O2 main.cpp' and 'clang -O2 main.cpp'.\n\n\
+ The option can be specified multiple times to run benchmarks for all \
+ possible parameter combinations.\n"
  ),
  )
  .arg(