make it compatible with yarn pnp

yarn plug and play does not use the node_modules directory:
therefore
```
#!/bin/bash
./node_modules/pre-commit/hook
RESULT=$?
[ $RESULT -ne 0 ] && exit 1
exit 0
```
is not working.

it outputs this
`.git/hooks/pre-commit: line 2: ./node_modules/pre-commit/hook: No such file or directory`


