✨ feat: Add markdown support plus /blog (#107)

Adds `/blog` page with support for `.md` and `.mdx` files.

What we learnt in setting this up will be packages in a package `@nestri/mdx` and used to set up the `/docs` and the `/terms` and `/privacy` routes

sst-env.d.ts

@@ -3,6 +3,10 @@
 import "sst"
 declare module "sst" {
   export interface Resource {
+    "CloudflareAccountId": {
+      "type": "sst.sst.Secret"
+      "value": string
+    }
   }
 }
 export {}