Add unit and integration tests

[nullchilly]

As testing configuration by hand or reviewing pull requests takes a lot of time, I would like a way to automatically check for:

• [ ] Simple configurations (transparency, compile, etc)
• [ ] Configurations that require plugin integrations (bufferline, lualine, etc) Refer to Special integrations

This will allow us to support backward compatibitity or if there exists a breaking change it should be mentioned in https://github.com/catppuccin/nvim/issues/260

[nullchilly]

@vinibispo I saw your repo ruby.nvim with plenary test

May I ask if you are able to tackle this issue

[vinibispo]

Sure

[nullchilly]

Added in the latest release https://github.com/catppuccin/nvim/releases/tag/v1.1.0