Add unique ID per post and an index to the db for that

src/main.ts

@@ -16,6 +16,7 @@ declare let marked: any;
 
 class Post {
   post_timestamp: Date;
+  post_id: string;
   author: string;
   author_id: string;
   text: string;
@@ -27,6 +28,7 @@ class Post {
 
   constructor(author: string, author_id: string, text: string, post_timestamp: Date, imageData: ArrayBuffer | null = null, importedFrom: "twitter" | null = null, importSource: any = null) {
     this.post_timestamp = post_timestamp;
+    this.post_id = generateID();
 
     this.author = author;
     this.author_id = author_id;