es6 module and custom event when line numbers are inserted

README.md

@@ -58,6 +58,17 @@ $(document).ready(function() {
 });
 ```
 
+You can also import the library as an es6 module:
+
+```js
+import hljs from 'highlight.js';
+
+import { decorateHljs } from 'highlightjs-line-numbers.js/src/decorator.es6.js';
+decorateHljs(hljs);
+hljs.highlightAll();
+hljs.initLineNumbersOnLoad();
+```
+
 If your needs cool style, add styles by taste:
 
 ```css
@@ -85,6 +96,19 @@ If your needs cool style, add styles by taste:
 }
 ```
 
+## Events
+
+There is one custom event fired when a code element has been augmented
+with line numbers. You can listen for it like so:
+
+```js
+const code = document.querySelector('code.my-code');
+code.addEventListener('line-numbers-inserted', (e) => {
+    // you can work with the line numbers modifications, now.
+});
+
+```
+
 ## Options
 
 After version 2.1 plugin has optional parameter `options` - for custom setup.
@@ -159,5 +183,20 @@ CSS selector                             |  description
 
 - [highlightjs-lang.js](https://github.com/wcoder/highlightjs-lang.js) — plugin to display language name with formatting;
 
+## Development: Building, and Basic Test of Code
+
+Build the project.
+
+    ./node_modules/.bin/gulp build
+
+Run http-server to test that the code is working:
+
+    ./node_modules/.bin/http-server -c-1 test
+
+That will start the server on localhost on port 8080, which
+you can navigate to. The index page
+invokes highlighting and this library, so you should see
+a C# snippet and line numbers.
+
 ---
 © 2023 Yauheni Pakala and [Community](https://github.com/wcoder/highlightjs-line-numbers.js/graphs/contributors) | MIT License

gulpfile.js

@@ -2,13 +2,21 @@ var gulp = require('gulp');
 var uglify = require('gulp-uglify');
 var rename = require("gulp-rename");
 var replace = require('gulp-replace');
+var rollup = require('rollup-stream');
+var buffer = require('vinyl-buffer');
+var source = require('vinyl-source-stream');
 
 gulp.task('build', function() {
-    return gulp.src('src/*.js')
+    return rollup({
+            input: 'src/highlightjs-line-numbers.js',
+            format: 'iife'
+        })
+        .pipe(source('highlightjs-line-numbers.js'))
+        .pipe(buffer())
         .pipe(uglify())
-        .pipe(replace('    ', ''))
         .pipe(rename({
             extname: '.min.js'
         }))
-        .pipe(gulp.dest('dist'));
+        .pipe(gulp.dest('dist'))
+        .pipe(gulp.dest('test'));
 });