Document pipefunc.

Author: tobiasraabe

docs/source/changes.md

@@ -13,6 +13,8 @@ releases are available on [PyPI](https://pypi.org/project/pytask) and
   control.
 - {pull}`656` fixes the return type of the hash function for {class}`PythonNode`s.
   Thanks to {user}`axtimhaus` for reporting the issue.
+- {pull}`657` documents `pipefunc`, another tool for executing graphs consisting out of
+  functions.
 
 ## 0.5.1 - 2024-07-20
 

docs/source/explanations/comparison_to_other_tools.md

@@ -126,3 +126,8 @@ General
 ## [zenml](https://github.com/zenml-io/zenml)
 
 ## [flyte](https://github.com/flyteorg/flyte)
+
+## [pipefunc](https://github.com/pipefunc/pipefunc)
+
+A tool for executing graphs made out of functions. More focused on computational
+compared to workflow graphs.