update readme for valgrind
@@ -350,7 +350,12 @@ executables. To build with valgrind support, use the `MI_VALGRIND=ON` cmake opti
```
This can also be combined with secure mode or debug mode.
-You can then run your programs directly under the `valgrind <myprogram>` tool.
+You can then run your programs directly under valgrind:
+
+```
+> valgrind <myprogram>
+```
+
If you rely on overriding `malloc`/`free` by mimalloc (instead of using the `mi_malloc`/`mi_free` API directly),
you also need to tell `valgrind` to not intercept those calls itself, and use:
