Remove or rename docs folder

[fbaldo31]

LICENSE file says

* All content residing under the "docs/" directory of this repository, if that
directory exists, is licensed under "Creative Commons: CC BY-SA 4.0 license".
* Content outside of the above mentioned directories or restrictions above is
available under the "MIT" license as defined below.

[fbaldo31]

In fact we can even:

• remove fully this folder and maybe write our doc in another folder like doc
• Keep it as is becausse cc license allow to modify but in this case we have to list what has been modified and add appropriate credits to Lens.

On my point of view we can delete the folder and rely to the official documentation since we didn't changed how the application is working nor the extension api. @gdubcs @colintufts @inquinity what do you think ?

[fbaldo31]

Related to #23 and #13