Add basic documentation (#14)

* Docs MVP

* Change to mintlify

* Add more docs

* Init docs

apps/docs/mint.json

@@ -0,0 +1,86 @@
+{
+  "$schema": "https://mintlify.com/schema.json",
+  "name": "Unsend",
+  "logo": {
+    "dark": "/logo/logo.svg",
+    "light": "/logo/logo.svg"
+  },
+  "favicon": "/favicon.svg",
+  "colors": {
+    "primary": "#000000",
+    "light": "#FFFFFF",
+    "dark": "#000000",
+    "anchors": {
+      "from": "#000000",
+      "to": "#000000"
+    }
+  },
+  "topbarLinks": [
+    {
+      "name": "Support",
+      "url": "mailto:hello@unsend.dev"
+    }
+  ],
+  "topbarCtaButton": {
+    "name": "Dashboard",
+    "url": "https://apps.unsend.dev"
+  },
+  "tabs": [
+    {
+      "name": "API Reference",
+      "url": "api-reference"
+    }
+  ],
+  "anchors": [
+    {
+      "name": "Github",
+      "icon": "github",
+      "url": "https://github.com/unsend-dev/unsend"
+    },
+    {
+      "name": "Community",
+      "icon": "discord",
+      "url": "https://discord.gg/BU8n8pJv8S"
+    }
+  ],
+  "navigation": [
+    {
+      "group": "Get Started",
+      "pages": [
+        "introduction"
+      ]
+    },
+    {
+      "group": "API Documentation",
+      "pages": [
+        "api-reference/introduction"
+      ]
+    },
+    {
+      "group": "Emails",
+      "pages": [
+        "api-reference/emails/get-email",
+        "api-reference/emails/send-email"
+      ]
+    },
+    {
+      "group": "Domains",
+      "pages": [
+        "api-reference/domains/get-domain"
+      ]
+    }
+  ],
+  "api": {
+    "baseUrl": "https://mintlify.com/api",
+    "auth": {
+      "method": "bearer"
+    },
+    "playground": {
+      "mode": "simple"
+    }
+  },
+  "footerSocials": {
+    "x": "https://x.com/unsend_dev",
+    "github": "https://github.com/unsend-dev"
+  }
+}