Change billing options to free

[rodrigoap2]

What problem is this solving?

As most of the connectors want to be published to all accounts, we are setting the default example with billingOptions: free to avoid private app installation problems.

How should this be manually tested?

Screenshots or example usage:

[vtex-io-ci-cd[bot]]

Hi! I'm VTEX IO CI/CD Bot and I'll be helping you to publish your app! 🤖

Please select which version do you want to release:

• [ ] Patch (backwards-compatible bug fixes)

• [ ] Minor (backwards-compatible functionality)

• [ ] Major (incompatible API changes)

And then you just need to merge your PR when you are ready! There is no need to create a release commit/tag.

• [ ] No thanks, I would rather do it manually 😞

[vtex-io-docs-bot[bot]]

Beep boop :robot:

I noticed you didn't make any changes at the docs/ folder

• [ ] There's nothing new to document :thinking:
• [ ] I'll do it later :disappointed:

In order to keep track, I'll create an issue if you decide now is not a good time

• [ ] I just updated :tada::tada: