add folding headings extension

.gitignore

@@ -9,6 +9,3 @@
 
 # libraries
 npm-debug.log
-
-index.js
-index.js.map

.npmignore

@@ -0,0 +1,3 @@
+src
+esbuild
+example

esbuild/build.mjs

@@ -0,0 +1,38 @@
+#!/usr/bin/env node
+
+import {build} from 'esbuild';
+import {sassPlugin} from 'esbuild-sass-plugin';
+
+import tsConfig from '../tsconfig.json' assert { type: "json" };
+
+const outDir = 'build/';
+
+/** @type {import('esbuild').BuildOptions}*/
+const common = {
+    bundle: true,
+    sourcemap: true,
+    target: tsConfig.compilerOptions.target,
+    tsconfig: './tsconfig.json',
+};
+
+/** @type {import('esbuild').BuildOptions}*/
+const runtime = {
+    ...common,
+    entryPoints: ['src/runtime/index.ts'],
+    outfile: outDir + 'runtime/index.js',
+    minify: true,
+    platform: 'browser',
+    plugins: [sassPlugin()],
+};
+
+/** @type {import('esbuild').BuildOptions}*/
+const plugin = {
+    ...common,
+    entryPoints: ['src/plugin/index.ts'],
+    outfile: outDir + 'plugin/index.js',
+    platform: 'node',
+    packages: 'external',
+}
+
+build(runtime);
+build(plugin);