Optimisations and updated readme

src/data/canvas-sizes.js

@@ -1,10 +1,10 @@
 async function fetchCanvasSizesData(pool) {
-  const [canvasSizes] = await pool.query('SELECT * FROM canvas_sizes ORDER BY width ASC, height ASC, name ASC');
+  const [canvasSizes] = await pool.query('SELECT id, name, width, height, created_at, modified_at, created_by, modified_by FROM canvas_sizes ORDER BY width ASC, height ASC, name ASC');
   return { canvasSizes };
 }
 
 async function fetchCanvasSizeById(pool, id) {
-  const [rows] = await pool.query('SELECT * FROM canvas_sizes WHERE id = ?', [id]);
+  const [rows] = await pool.query('SELECT id, name, width, height, created_at, modified_at, created_by, modified_by FROM canvas_sizes WHERE id = ?', [id]);
   return rows[0] || null;
 }