feature. add taco icon to GLB logo section

Author: ktkfree

docs/assets/taco_icon.png

@@ -4,6 +4,7 @@ repo_url: https://github.com/openinfradev/decapod-docs
 theme:
   language: kr
   name: material
+  logo: assets/taco_symbol.png
   palette: 
    - scheme: default 
      toggle:
@@ -61,4 +62,4 @@ nav:
     - getting-started/customize-yaml.md
     - getting-started/deploying.md
   - troubleshooting.md
-  - glossary.md
+  - glossary.md