Use Qiskit sphinx theme (#306)

* use qiskit sphinx theme

* don't pin qiskit-sphinx-theme version

docs/conf.py

@@ -27,25 +27,19 @@
     "sphinx_autodoc_typehints",
     "myst_parser",
     "nbsphinx",
+    "qiskit_sphinx_theme",
 ]
 
 exclude_patterns = ["_build", "**.ipynb_checkpoints"]
 
 # HTML output options
-html_theme = "furo"
+html_theme = "qiskit-ecosystem"
+html_title = f"{project} {release}"
 html_theme_options = {
-    "footer_icons": [
-        {
-            "name": "GitHub",
-            "url": "https://github.com/qiskit-community/ffsim",
-            "html": """
-                <svg stroke="currentColor" fill="currentColor" stroke-width="0" viewBox="0 0 16 16">
-                    <path fill-rule="evenodd" d="M8 0C3.58 0 0 3.58 0 8c0 3.54 2.29 6.53 5.47 7.59.4.07.55-.17.55-.38 0-.19-.01-.82-.01-1.49-2.01.37-2.53-.49-2.69-.94-.09-.23-.48-.94-.82-1.13-.28-.15-.68-.52-.01-.53.63-.01 1.08.58 1.23.82.72 1.21 1.87.87 2.33.66.07-.52.28-.87.51-1.07-1.78-.2-3.64-.89-3.64-3.95 0-.87.31-1.59.82-2.15-.08-.2-.36-1.02.08-2.12 0 0 .67-.21 2.2.82.64-.18 1.32-.27 2-.27.68 0 1.36.09 2 .27 1.53-1.04 2.2-.82 2.2-.82.44 1.1.16 1.92.08 2.12.51.56.82 1.27.82 2.15 0 3.07-1.87 3.75-3.65 3.95.29.25.54.73.54 1.48 0 1.07-.01 1.93-.01 2.2 0 .21.15.46.55.38A8.013 8.013 0 0 0 16 8c0-4.42-3.58-8-8-8z"></path>
-                </svg>
-            """,  # noqa: E501
-            "class": "",
-        },
-    ],
+    "source_repository": "https://github.com/qiskit-community/ffsim/",
+    "source_branch": "main",
+    "source_directory": "docs/",
+    "sidebar_qiskit_ecosystem_member": True,
 }
 
 # nbsphinx options (for tutorials)

pyproject.toml

@@ -39,7 +39,6 @@ Documentation = "https://qiskit-community.github.io/ffsim/"
 [project.optional-dependencies]
 dev = [
     "coverage",
-    "furo",
     "maturin",
     "mypy",
     "myst-parser",
@@ -48,6 +47,7 @@ dev = [
     "pre-commit",
     "pytest",
     "qiskit[visualization]",
+    "qiskit-sphinx-theme",
     "ruff == 0.6.2",
     "sphinx",
     "sphinx-autodoc-typehints",