Automate docs generation using solidity-docgen.

[ealmansi]

🎉 Description

Documentation is currently generated manually by running the solidity-docgen project. It would be great if we automated this process as part of the build step on every major and minor version update.

• 📈 This is a feature request.

[ealmansi]

cc @ajsantander

[eordano]

Not sure about this: It would pollute the repository with generated files. Perhaps after dev installs? What if instead the documentation is published to github pages?

[nventuro]

This is already happening as part of the docsite revamp @frangio is carrying out.

[frangio]

To be clear, this is already happening today. The docsite is deployed automatically.