Update link to numpydoc example.py (#7395)

* Fix pull request template link

* Update .github/PULL_REQUEST_TEMPLATE.md

---------

Co-authored-by: Jarrod Millman <jarrod.millman@gmail.com>

.github/PULL_REQUEST_TEMPLATE.md

@@ -11,7 +11,7 @@
 <!-- Before pull requests can be merged, they should provide: -->
 
 - A descriptive but concise pull request title
-- [Docstrings for all functions](https://github.com/numpy/numpy/blob/master/doc/example.py)
+- [Docstrings for all functions](https://github.com/numpy/numpydoc/blob/main/doc/example.py)
 - [Unit tests](https://scikit-image.org/docs/dev/development/contribute.html#testing)
 - A gallery example in `./doc/examples` for new features
 - [Contribution guide](https://scikit-image.org/docs/dev/development/contribute.html) is followed