[Reminder] Allow footer and title modification

Module will be more more flexible

data/migration/v8-v9/migration.sql

@@ -1,6 +1,10 @@
 ALTER TABLE user_config
   ADD COLUMN remaind_upvote BOOLEAN DEFAULT TRUE
 
+ALTER TABLE reminders
+  ADD COLUMN title TEXT DEFAULT NULL,
+  ADD COLUMN footer TEXT DEFAULT NULL
+
 -- Topgg Data {{{
 CREATE TABLE IF NOT EXISTS topgg(
   voteid SERIAL PRIMARY KEY,

data/schema.sql

@@ -167,7 +167,9 @@ CREATE TABLE reminders(
   content TEXT NOT NULL,
   message_link TEXT,
   interval INTEGER,
-  created_at TIMESTAMP DEFAULT (now() at time zone 'utc')
+  created_at TIMESTAMP DEFAULT (now() at time zone 'utc'),
+  title TEXT DEFAULT NULL,
+  footer TEXT DEFAULT NULL
 );
 CREATE INDEX reminder_users ON reminders (userid);
 -- }}}