Add documentation for pre-push hooks

[ruslanpashkov]

The current Husky documentation mentions that hooks can run on push, but there is no explicit mention of pre-push hooks or how to implement them. This makes it unintuitive for new users who are only introduced to pre-commit in the documentation.

Steps to Reproduce

1. Check the Husky documentation
2. Search for pre-push
3. Notice that there is no clear example of how to set up pre-push hooks

Expected Behavior

The documentation should provide an example of how to set up a pre-push hook, similar to how pre-commit is documented.

Context

While it's possible to set up pre-push hooks using native Git hooks, one of Husky's main benefits is making Git hooks easier to manage and share across teams. Having clear documentation about pre-push hooks would help users understand how to leverage Husky's advantages over manual Git hook setup.

Suggested Fix

Add a section for pre-push hooks with a basic example, like:

echo "npm test" > .husky/pre-push

This will help new users understand how to use Husky beyond pre-commit.