Support for `--strict` in helmlint hook

**Describe the solution you'd like**
`helm` supports the `--strict` option for failing on warnings when linting. It would be nice if the pre-commit hook also supported this. I've tried messing around with it but it looks like the only way to support this is a change in the `helmlint.sh` file.

**Describe alternatives you've considered**
Not sure if there are any alternatives, as the `helm` command is called directly in the script

**Additional context**
Add any other context or screenshots about the feature request here.