chore: Added overview schema for dark mode

Author: GermanMT

_config.yml

@@ -2,7 +2,7 @@ title: Secure Chain
 remote_theme: just-the-docs/just-the-docs@v0.5.2
 logo: "/assets/securechain/logos/securechain-logo.png"
 url: https://securechaindev.github.io
-color_scheme: light
+color_scheme: dark
 color_scheme_toggle: true
 aux_links:
   GitHub Organization: https://github.com/securechaindev

assets/securechain/figs/overview_dark.png

@@ -18,7 +18,10 @@ We provide tools to:
 ## How it works?
 
 <p align="center">
-  <img src="/assets/securechain/figs/overview.png" alt="Secure Chain Overview" width="1000"/>
+  <picture>
+    <source srcset="/assets/securechain/figs/overview_dark.png" media="(prefers-color-scheme: dark)">
+    <img src="/assets/securechain/figs/overview_light.png" alt="Secure Chain Overview" width="1000"/>
+  </picture>
   <p align="center"><strong>Secure Chain Architecture Overview</strong></p>
 </p>