update icons and logos

Signed-off-by: Jim Zhang <jim.zhang@kaleido.io>

Author: jimthematrix

doc-site/docs/assets/paladin-icon-light.png

@@ -43,4 +43,5 @@
     display: none;
 }
 
+.md-header__button.md-logo img[alt=zeto] { height: 2rem; }
 img[alt=pqc] { width: 75px; border-radius: 15px; }

doc-site/docs/assets/paladin-logo-dark.svg

@@ -4,9 +4,9 @@ repo_url: https://github.com/hyperledger-labs/zeto
 theme:
   name: material
   custom_dir: overrides
-  logo: assets/paladin-logo-light.svg
-  logo_dark: assets/paladin-logo-dark.svg
-  favicon: assets/paladin-icon-light.png
+  logo: assets/zeto-logo-light.jpg
+  logo_dark: assets/zeto-logo-dark.jpg
+  favicon: assets/zeto-icon.jpg
   icon:
     repo: fontawesome/brands/github
   palette:

doc-site/docs/assets/paladin-logo-light.svg

@@ -21,5 +21,5 @@
 -->
 
 <!-- Logo -->
-<img src="{{ config.theme.logo_dark | url }}#only-dark" alt="Paladin" />
-<img src="{{ config.theme.logo | url }}#only-light" alt="Paladin" />
+<img src="{{ config.theme.logo_dark | url }}#only-dark" alt="zeto" />
+<img src="{{ config.theme.logo | url }}#only-light" alt="zeto" />