feat: alternative of existing skeleton

[WasinWatt]

• cmd just call <command>.New() to start the flow, no extra setup call (complicated stuff should be inside <command>
• each subfoler in models is responsible for a specific root command that needs tea.model
• each root command contains its own state (defined in <rootcommand>/state.go , passing state is simple. Take a look at demo subfolder
• sub command models live inside root command's subfolder. Ex. vm_select.go lives in models/demo

please be mindful that this repo should/could be open-sourced in the future.

Good characteristics of a good skeleton.

• Files and folders are organized. Devs should know how to create files / how to name / etc. just by reading the code. Feature development should be easy and can be parallel
• Easy to read and extend ideas from. Global storage thing is too much IMO.

General Feedback

• Function like ResetStates shouldn't exist in implementation files (can live in a mock struct or test files)
• Use Mocks & good mock library