Add submissions table.

highscores_database.sql

@@ -42,4 +42,13 @@ CREATE TABLE Scores(
    CategoryId int unsigned not null,
    FOREIGN KEY (CategoryId) REFERENCES Categories(CategoryId) ON DELETE CASCADE,
    PRIMARY KEY (CategoryId, UserName)
+);
+
+CREATE TABLE Submissions(
+   CategoryId int unsigned not null,
+   GroupId int unsigned not null,
+   GuildId int unsigned not null,
+   MessageId int unsigned not null,
+   Score varchar(30) not null, -- Score is stored as a string until converted during submission
+   UserName varchar(30) not null
 );