Refactor documentation requirements in requirements.txt to remove unnecessary build configuration

Author: rbeucher

docs/requirements.txt

@@ -1,24 +1,9 @@
-version: 2
-
-build:
-  os: ubuntu-22.04
-  tools:
-    python: "3.13"
-
-sphinx:
-  configuration: docs/source/conf.py
-  fail_on_warning: false
-
-formats:
-  - pdf
-  - epub
-
-python:
-  install:
-    - method: pip
-      path: .
-      extra_requirements:
-        - docs
+###############################
+# Documentation requirements  #
+###############################
+# Tip: For local builds you can also run:
+#   pip install -e .[docs]
+# which uses the extras defined in pyproject.toml
 
 # Core documentation dependencies
 sphinx>=7.0.0