Add gradiant on hero image background

Author: Gugustinette

docs/.vitepress/theme/custom.css

@@ -41,6 +41,10 @@
   --vp-button-brand-hover-text: #0F172A;
   --vp-button-brand-active-text: #0F172A;
   --vp-button-brand-hover-bg: #03C169;
+
+  /* Hero Background Image */
+  --vp-home-hero-image-background-image: linear-gradient(-45deg, #00dc807b 40%, #00dc801a 50%);
+  --vp-home-hero-image-filter: blur(44px);
 }
 
 /* Leaflet specific style */