docs: add visitor map configuration to README and update docs.md

- Added visitor map section to README.md after GitHub Contributions Graph
- Updated visitor map description in content/pages/docs.md with privacy details
- Documents configuration options in src/config/siteConfig.ts
- Explains Netlify geo detection and theme-aware colors

netlify/edge-functions/geo.ts

@@ -0,0 +1,32 @@
+import type { Context } from "@netlify/edge-functions";
+
+// Returns the user's geo location from Netlify's automatic geo headers
+// Privacy friendly: only returns city/country/coordinates, no IP address stored
+export default async function handler(
+  _request: Request,
+  context: Context,
+): Promise<Response> {
+  // Netlify provides geo data automatically via context.geo
+  const geo = context.geo;
+
+  const data = {
+    city: geo?.city || null,
+    country: geo?.country?.code || null,
+    countryName: geo?.country?.name || null,
+    latitude: geo?.latitude || null,
+    longitude: geo?.longitude || null,
+  };
+
+  return new Response(JSON.stringify(data), {
+    headers: {
+      "Content-Type": "application/json",
+      "Cache-Control": "private, max-age=3600",
+      "Access-Control-Allow-Origin": "*",
+    },
+  });
+}
+
+export const config = {
+  path: "/api/geo",
+};
+