Update environments article with new environment templates method

[banchan86]

The environments article needs to be updated with the new environment templates method which significantly streamlines the environment setup process as outlined in bonsai-rx/bonsai#1251 and bonsai-rx/bonsai#1701.

However, at issue is what to do with the existing portable method of creating environments, which many existing users might already be familiar with. They might prefer since it doesn't require the installation of additional tools or command line familiarity. They may also not use environments to the extent that they feel they need to fiddle around with the template method.