Switch logo to red FEBio emblem and add favicon

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01U96z31ZadrrQ3YtU7br22M

Author: Wesley-Jakob-Gilbert

build.py

@@ -181,6 +181,7 @@ def write_nav(f, items, indent):
     f.write("theme:\n")
     f.write("  name: material\n")
     f.write("  logo: febio.png\n")
+    f.write("  favicon: febio.png\n")
     f.write("  palette:\n")
     f.write("    primary: indigo\n")
     f.write("    accent: indigo\n")

docs/febio.png

@@ -4,6 +4,7 @@ site_author: FEBio Team
 theme:
   name: material
   logo: febio.png
+  favicon: febio.png
   palette:
     primary: indigo
     accent: indigo