Add minification (#73)

* added gulp for es6 transpiling

* ♻️ Added minify css and html tasks

.gitignore

@@ -0,0 +1,2 @@
+node_modules
+build

gulpfile.js

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+const gulp = require("gulp");
+const uglify = require("gulp-uglify");
+const babel = require("gulp-babel");
+let cleanCSS = require("gulp-clean-css");
+const htmlmin = require("gulp-htmlmin");
+const del = require("del");
+
+gulp.task("clean", done => {
+  del.sync("build/**/*");
+  done();
+});
+
+gulp.task("minify-scripts", done => {
+  gulp
+    .src(["*.js", "!gulpfile.js"])
+    .pipe(
+      babel({
+        presets: ["@babel/preset-env"]
+      })
+    )
+    .pipe(uglify())
+    .pipe(gulp.dest("build"));
+  done();
+});
+
+gulp.task("minify-css", done => {
+  gulp
+    .src("*.css")
+    .pipe(cleanCSS())
+    .pipe(gulp.dest("build"));
+  done();
+});
+
+gulp.task("minify-html", done => {
+  gulp
+    .src("*.html")
+    .pipe(htmlmin({ collapseWhitespace: true }))
+    .pipe(gulp.dest("build"));
+  done();
+});
+
+gulp.task("copy", done => {
+  gulp
+    .src(["manifest.json", "images/**/*", "Roboto/**/*", "utils/**/*"], {
+      base: "."
+    })
+    .pipe(gulp.dest("build"));
+  done();
+});
+
+gulp.task(
+  "default",
+  gulp.series(
+    "clean",
+    "minify-scripts",
+    "minify-css",
+    "minify-html",
+    "copy",
+    done => done()
+  )
+);