feat: support ie 11 (#809)

Author: zhensherlock

babel.config.js

@@ -5,6 +5,7 @@ const presets = [
       useBuiltIns: 'usage',
       corejs: { version: 3 },
       targets: [
+        'ie >= 11',
         '> 1%',
         'Firefox ESR',
         'last 4 versions',

build/index.mjs

@@ -0,0 +1,2 @@
+export * from './banner.mjs'
+export * from './output.mjs'

build/output.mjs

@@ -0,0 +1,61 @@
+import terser from '@rollup/plugin-terser'
+import { banner } from './banner.mjs'
+
+export const generateOutputs = (section = '') => {
+  const path = section === ''? 'dist' : `dist/${section}`
+  return [
+    {
+      name: 'WatermarkPlus',
+      format: 'esm',
+      file: `${path}/index.esm.js`,
+      sourcemap: true,
+      banner
+    },
+    {
+      name: 'WatermarkPlus',
+      format: 'umd',
+      file: `${path}/index.umd.js`,
+      sourcemap: true,
+      banner
+    },
+    {
+      name: 'WatermarkPlus',
+      format: 'iife',
+      file: `${path}/index.iife.js`,
+      sourcemap: true,
+      banner
+    },
+    {
+      name: 'WatermarkPlus',
+      format: 'cjs',
+      file: `${path}/index.cjs.js`,
+      sourcemap: true,
+      banner
+    },
+    // min
+    {
+      name: 'WatermarkPlus',
+      format: 'esm',
+      file: `${path}/index.esm.min.js`,
+      plugins: [terser()]
+    },
+    {
+      name: 'WatermarkPlus',
+      format: 'umd',
+      file: `${path}/index.umd.min.js`,
+      plugins: [terser()]
+    },
+    {
+      name: 'WatermarkPlus',
+      format: 'iife',
+      file: `${path}/index.iife.min.js`,
+      plugins: [terser()]
+    },
+    {
+      name: 'WatermarkPlus',
+      format: 'cjs',
+      file: `${path}/index.cjs.min.js`,
+      plugins: [terser()]
+    }
+  ]
+}