add sqlite database and message editing support

migrations/2023-11-05-222006_create_posts/down.sql

@@ -0,0 +1 @@
+DROP TABLE posts;

migrations/2023-11-05-222006_create_posts/up.sql

@@ -0,0 +1,7 @@
+CREATE TABLE posts (
+    announcement_id TEXT NOT NULL,
+    webhook_id UNSIGNED BIG INT NOT NULL,
+    message_id UNSIGNED BIG INT NOT NULL,
+    last_updated TIMESTAMP NOT NULL,
+    PRIMARY KEY (announcement_id, webhook_id)
+);