Use SQLx migrations

migrations/20210922000000_macro.sql

@@ -0,0 +1,11 @@
+CREATE TABLE macro (
+    id INT UNSIGNED AUTO_INCREMENT,
+    guild_id INT UNSIGNED NOT NULL,
+
+    name VARCHAR(100) NOT NULL,
+    description VARCHAR(100),
+    commands TEXT NOT NULL,
+
+    FOREIGN KEY (guild_id) REFERENCES guilds(id) ON DELETE CASCADE,
+    PRIMARY KEY (id)
+);