ci: add basic workflow

[felipebergamin]

Description

Implements a GitHub Actions Workflow to check code healthy.

This workflow performs the following steps:

1. Setup: run yarn install and yarn install-peers
2. Build: runs yarn build, which generates both esm and cjs distributions
3. dry run a publish: performs a publish action without actually publishing to npm, prints what would be published

In the end of steps 1 and 2, checks if git workspace is clean.

[cabelitos]

IMO we should only publish in case we add a git tag to commit and not on every merge/release.

[felipebergamin]

good point! I'll change this job to run when a git tag is pushed