Docs builder

[victorhmp]

What is the purpose of this pull request?

Add docs builder and move README to /docs.

Types of changes

• Bug fix (a non-breaking change which fixes an issue)
• New feature (a non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Requires change to documentation, which has been updated accordingly.

[vtex-io-ci-cd]

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

• Minor

• Major

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 😞