Include other sphinx extensions in extra.

pyproject.toml

@@ -13,8 +13,11 @@ version = "0.1.0"
 
 [tool.poetry.dependencies]
 networkx = "^2.5"
+pylint = { version = "^2.6.0", optional = true }
 python = "^3.7.0"
-sphinx-celery = {version = "^2.0.0", optional = true}
+sphinx-autodoc-typehints = { version = "^1.11.1", optional = true }
+sphinx-celery = { version = "^2.0.0", optional = true }
+sphinx-pyreverse = { version = "^0.0.13", optional = true }
 transitions = { version = "^0.8.7", extras = ['diagrams'], optional = true }
 transitions-anyio = "^0.2.0"
 wrapt = "^1.12.1"
@@ -24,7 +27,6 @@ autoflake = "^1.4"
 black = "^20.8b1"
 isort = "^5.7.0"
 mock = { version = "^4.0.3", python = "< 3.8" }
-pylint = "^2.6.0"
 pytest = "^6.0"
 pytest-cov = "^2.11.1"
 pytest-github-actions-annotate-failures = "^0.1.1"
@@ -34,15 +36,12 @@ pytest-subtests = "^0.3"
 pytest-timeout = "^1.4.2"
 pytest-xdist = "^2.2.0"
 pyupgrade = "^2.7.4"
-sphinx-autodoc-typehints = "^1.11.1"
-sphinx-celery = "^2.0.0"
-sphinx-pyreverse = "^0.0.13"
 toml-sort = "^0.18.0"
 trio = "^0.17"
 
 [tool.poetry.extras]
 diagrams = ["transitions"]
-readthedocs = ["sphinx-celery"]
+readthedocs = ["sphinx-celery", "sphinx-autodoc-typehints", "sphinx-pyreverse", "pylint"]
 
 [tool.pytest.ini_options]
 filterwarnings = [