update all links to docs.circuitpython.org

Author: jepler

.github/PULL_REQUEST_TEMPLATE/adafruit_circuitpython_pr.md

@@ -4,7 +4,7 @@
 
 Thank you for contributing! Before you submit a pull request, please read the following.
 
-Make sure any changes you're submitting are in line with the CircuitPython Design Guide, available here: https://circuitpython.readthedocs.io/en/latest/docs/design_guide.html
+Make sure any changes you're submitting are in line with the CircuitPython Design Guide, available here: https://docs.circuitpython.org/en/latest/docs/design_guide.html
 
 If your changes are to documentation, please verify that the documentation builds locally by following the steps found here: https://adafru.it/build-docs