`.venv` folder created from Python Envs panel isn't git ignored by default

[cwebster-99]

I have a repo open and when I use the Create Environment entry points from this extension the .venv is added to my source control. When I create an environment without this extension installed it is automatically ignored. We should carry over the same behavior.

[eleanorjboyd]

adding support so a .gitignore will be added for both venvs created and conda (if the conda env is created within one of the project's workspaces)