Patch/build docs (#25)

* add pixi job

* add explicit build.commands

Author: ethan-shanahan

.readthedocs.yml

@@ -31,9 +31,3 @@ sphinx:
 #       path: .
 #       extra_requirements:
 #         - docs
-# python:
-#   install:
-#     - method: pip
-#       path: .
-#       extra_requirements:
-#         - docs