Update README.md

[ferdymercury]

https://forum.kicad.info/t/warning-avoid-all-links-to-kicad-pcb-org-use-kicad-org/31521

Thank you for creating a pull request to contribute to the code!

Please provide the following informations:

• Describe what the change does, this will speed up the integration;
• Describe what parts of the code were modified, this will help me to understand
  possible risks of integration;
• Describe any known limitations with your change, for example if the change
  requires special conditions to function as intended.

I will try to test and integrate the change as soon as I can, but be aware that I work
on these projects on my very limited spare time.
There is no need to bump or check in on a pull request.

Don't be worried if the request is closed or not integrated, I may have some other
priorities / ideas / intentions regarding the development line of this repository.
You can always fork this repository and GitHub makes it easy to keep your changes in
a forked repo.

Delete this text before submiting the pull request.