1312 Accelerate documentation build (#1313)

- Mocking dependencies for sphinx build
- set collapse_navigation to true leads to ~50% faster build

Co-authored-by: Kilian Volmer <13285635+kilianvolmer@users.noreply.github.com>

Author: HenrZu

docs/source/conf.py

@@ -92,12 +92,30 @@
 html_theme = 'sphinx_rtd_theme'
 html_logo = "../memilio-small.png"
 html_theme_options = {
-    "collapse_navigation": False,
+    "collapse_navigation": True,
     "logo_only": True,
     "style_nav_header_background": "#f8f9fb",
 }
 
-
+# Mock heavy dependencies to speed up build
+autodoc_mock_imports = [
+    "numpy",
+    "scipy",
+    "pandas",
+    "matplotlib",
+    "tensorflow",
+    "scikit-learn",
+    "h5py",
+    "tables",
+    "geopandas",
+    "pyarrow",
+    "PyQt6",
+    "wget",
+    "twill",
+    "folium",
+    "mapclassify",
+    "imageio",
+]
 
 # -- Options for EPUB output
 epub_show_urls = 'footnote'