Folder Pluto/ needs to be created first

In the description of installing [*Ansible*](https://github.com/ct-Open-Source/telerec-t-base#install-ansible) you first have to create the folder `Pluto` before cd to it.

(It's only a small issue, but it can become a big problem, if you are a newbie to Python or Ansible)

Start at the repository's Ansible installation instructions linked in the issue, especially the step that changes into Pluto. Update the instructions so the Pluto folder is created before entering it. Done means a newcomer can follow the sequence without encountering a missing-directory error.

Written by the indexing model from the issue text.