dep: Move documentation dependencies to separate group

This is handy in CI where for documentation generation,
we only want to install the relevant dependencies.

Author: kissgyorgy

pyproject.toml

@@ -38,6 +38,12 @@ pyright = "^0.0.12"
 pre-commit = "^2.15.0"
 pytest-cov = "^3.0.0"
 setuptools-rust = "^1.1.2"
+
+
+[tool.poetry.group.docs]
+optional = true
+
+[tool.poetry.group.docs.dependencies]
 mkdocs-material = "8.5.10"
 mkdocstrings = "^0.19.1"
 pillow = "^9.4.0"