`esphome` told me:
```
WARNING Calling ESPHome with the configuration before the command is deprecated and will be removed in the future.
WARNING Please instead use:
WARNING esphome wizard livingroom.yaml
```
Changing the instruction of "pip install" to "pip3 install" instead, due to the warning: "You're using ESPHome with python 2. Support for python 2 is deprecated and will be removed in 1.15.0. Please reinstall ESPHome with python 3.6 or higher."
* Small changes from proofreading.
* Proofreading changes.
* Correction from travis checks
* Update guides/getting_started_command_line.rst
Co-Authored-By: Otto Winter <otto@otto-winter.com>
* More proofreading changes.
* More proofreading changes.
* Minor corrections
