Add option to store config and OpenAI keys in home folder

[AleksandarFaraj]

I want to discuss the necessity to run tzap init at the start of each project and the expectation for users to place the .env file in the root folder as well as having the created .tzap-data/config.json in root (or a parent folder, as seen in 'cli/cmd/cmdutil/configwalker.go' where cmdutil.SearchForTzapincludeAndGetRootDir() function is defined.)

There are a few possible improvements to enhance the experience:

1. Offer an option to users to choose whether to globally install tzap configurations or keep it on a per-project basis. This improvement would not disrupt the current behavior too much but would allow more flexibility for users.
2. Reviewing the handling of the config/.env file. Consider developing a way to manage the config/.env file more effectively. For instance, tzap could look for an .env file in the project folder first before falling back to the home folder.

This issue should not move .tzap-data folder as a whole, but rather offer a strategy for config.json and .env files.