Added gulp and postcss

gulpfile.js

@@ -0,0 +1,32 @@
+const del = require('del');
+const gulp = require('gulp');
+const postcss = require('gulp-postcss');
+const sass = require('gulp-sass')(require('sass'));
+
+const src = 'src/stylesheets/main.scss';
+const dest = 'public/css';
+
+gulp.task('styles', () => {
+	const plugins = [
+		require('autoprefixer'),
+	];
+
+	return gulp.src(src)
+		.pipe(sass().on('error', sass.logError))
+		.pipe(postcss(plugins))
+		.pipe(gulp.dest(dest));
+});
+
+gulp.task('clean', () => {
+	return del([
+		dest
+	]);
+});
+
+gulp.task('default', gulp.series([ 'clean', 'styles' ]));
+
+gulp.task('watch', () => {
+	gulp.watch('src/stylesheets/**/*.scss', (done) => {
+		gulp.series([ 'clean', 'styles' ])(done);
+	});
+});