Follow best practices for versioning

[matifali]

For versioning provider releases, let's follow the terraform developer best practices.

This suggests bumping minor when we add new attributes to existing resources or add new resources without any breaking changes.

We recently released a new attribute, hidden, for the resource coder_app without bumping the minor version.

[matifali]

@johnstcn I guess we can close this after we release 2.0.