fix optional comment and add poetry specific group

Author: radoering

README.md

@@ -63,12 +63,23 @@ python = ">=3.9,<4.0"
 # Version-specific dependencies with prereleases allowed
 tomli = { allow-prereleases = true }
 
-# Dependency groups are supported for organizing your dependencies (PEP 735)
+# Dependency groups are supported for organizing your dependencies
 [dependency-groups]
 dev = ["pytest (>=7.1.2,<8.0.0)", "pytest-cov (>=3.0,<4.0)"]
+docs = ["Sphinx (>=5.1.1,<6.0.0)"]
+
 # ...and can be installed only when explicitly requested
 # via 'poetry install --with docs'
-docs = ["Sphinx (>=5.1.1,<6.0.0)"]
+[tool.poetry.group.docs]
+optional = true
+
+# Alternatively, you can use Poetry specific syntax
+# to specify dependency groups
+[tool.poetry.group.lint]
+optional = true
+
+[tool.poetry.group.lint.dependencies]
+ruff = ">=0.10.0"
 ```
 
 ## Installation