docs: update Sphinx theme from Press to Furo

Replace sphinx-press-theme with Furo theme for better maintenance
and modern aesthetic. Furo has active community support and is used
by fellow ASWF project OpenImageIO.

Changes:
- Update docs/requirements.txt to use furo instead of sphinx-press-theme
- Update docs/conf.py html_theme from 'press' to 'furo'
- Adjust theme options for Furo compatibility

Issue Number: close #1872

Signed-off-by: Madduri, Pavan <[email protected]>

Author: pmady

docs/conf.py

@@ -115,14 +115,14 @@
 
 # -- Options for HTML output --------------------------------------------------
 
-html_theme = "press"
+html_theme = "furo"
 html_logo = "_static/ocio_b.svg"
 html_static_path = ["_static"]
 
 html_theme_options = {
-  "external_links": [
-      ("Github", "https://github.com/AcademySoftwareFoundation/OpenColorIO"),
-  ]
+  "source_repository": "https://github.com/AcademySoftwareFoundation/OpenColorIO",
+  "source_branch": "main",
+  "source_directory": "docs/",
 }
 
 # -- Options for LaTeX output -------------------------------------------------

docs/requirements.txt

@@ -8,7 +8,7 @@ sphinx<=7.1.2
 six
 testresources
 recommonmark
-sphinx-press-theme
+furo
 sphinx-tabs
 breathe
 setuptools<68.0.0