Update .gitignore, add dist directory

dist/lib/grab-duplicate-safe-insert-sql.d.ts

@@ -0,0 +1,7 @@
+type Params = {
+    sql: string;
+    table: string;
+    data: any | any[];
+};
+export default function ({ sql: passedSql, table, data }: Params): Promise<string>;
+export {};