Add OG and Twitter Card markup, generate OG profile images

closes #2

models/article.ts

@@ -28,6 +28,11 @@ export default class Article {
     return tag ? tag[1] : "Untitled";
   }
 
+  get image(): string {
+    const tag = this.event.tags.find((t) => t[0] === "image");
+    return tag ? tag[1] : undefined;
+  }
+
   get summary(): string {
     const tag = this.event.tags.find((t) => t[0] === "summary");
     return tag ? tag[1] : "";

models/profile.ts

@@ -1,5 +1,5 @@
 import { nip19, NostrEvent as NEvent } from "@nostr/tools";
-// import { NEvent } from "../nostr.ts";
+import config from "../config.ts";
 
 export interface ProfileData {
   name?: string;
@@ -54,4 +54,12 @@ export default class Profile {
   get npub(): string {
     return nip19.npubEncode(this.pubkey);
   }
+
+  get profileUrl(): string {
+    return `${config.base_url}/@${this.username}`;
+  }
+
+  get ogImageUrl(): string {
+    return `${config.base_url}/assets/g/img/og-p-${this.event.id}.png`;
+  }
 }