Notice that undistortion of images is done on robot's side on Ned2 since v5.8.3-b62

[ctmbl]

closes #14

What still need to be checked:

• find the Ned2 version that introduced this change
• check if it's true for other robots (Ned, Ned 3Pro, etc)
• check that I changed every occurrence of undistort_image in the docs

Feel free to suggest a better commit/PR title I struggled finding an explicit one

[jmottier-niryo]

Thank you for your contribution. Unfortunately, these changes have already been done on our side and will be available in the next PyNiryo release.
To avoid this kind of problem, we'll from now indicate in the issue when it's treated on our side.