refactor: extract plugins into separate files

plugins/flex-basis-plugin.js

@@ -0,0 +1,11 @@
+let plugin = require("tailwindcss/plugin");
+
+let flexBasisPlugin = plugin(function ({ addBase, addUtilities }) {
+  let values = [10, 20, 30, 40, 50, 60, 70, 80, 90, 100];
+
+  values.forEach((value) => {
+    addUtilities({ [`.flex-basis-${value}`]: { flexBasis: `${value}%` } });
+  });
+});
+
+module.exports = flexBasisPlugin;