feat!: manifest.json should be generated by cli-plugin-pwa (#2981)

BREAKING CHANGE:
For those who changed their `manifest.json` in `public/` directory, their changes will be ignored.

Author: aweikalee

packages/@vue/cli-plugin-pwa/README.md

@@ -71,6 +71,19 @@ file, or the `"vue"` field in `package.json`.
 
     The path of app’s manifest.
 
+- **pwa.manifestOptions**
+
+  - Default: `{}`
+
+    The object will be used to generate the `manifest.json`
+
+    If the following attributes are not defined in the object, the options of `pwa` or default options will be used instead.
+      - name: `pwa.name`
+      - short_name: `pwa.name`
+      - start_url: `'.'`
+      - display: `'standalone'`
+      - theme_color: `pwa.themeColor`
+
 - **pwa.iconPaths**
 
   - Defaults:

packages/@vue/cli-plugin-pwa/generator/template/public/manifest.json

@@ -7,7 +7,26 @@ const defaults = {
   appleMobileWebAppCapable: 'no',
   appleMobileWebAppStatusBarStyle: 'default',
   assetsVersion: '',
-  manifestPath: 'manifest.json'
+  manifestPath: 'manifest.json',
+  manifestOptions: {}
+}
+
+const defaultManifest = {
+  icons: [
+    {
+      "src": "./img/icons/android-chrome-192x192.png",
+      "sizes": "192x192",
+      "type": "image/png"
+    },
+    {
+      "src": "./img/icons/android-chrome-512x512.png",
+      "sizes": "512x512",
+      "type": "image/png"
+    }
+  ],
+  start_url: '.',
+  display: 'standalone',
+  background_color: "#000000"
 }
 
 const defaultIconPaths = {
@@ -109,6 +128,30 @@ module.exports = class HtmlPwaPlugin {
 
         cb(null, data)
       })
+
+
+    })
+
+    compiler.hooks.emit.tapAsync(ID, (data, cb) => {
+      const {
+        name,
+        themeColor,
+        manifestPath,
+        manifestOptions
+      } = this.options
+      const publicOptions = {
+        name,
+        short_name: name,
+        theme_color: themeColor
+      }
+      const outputManifest = JSON.stringify(
+        Object.assign(publicOptions, defaultManifest, manifestOptions)
+      )
+      data.assets[manifestPath] = {
+        source: () => outputManifest,
+        size: () => outputManifest.length
+      }
+      cb(null, data)
     })
   }
 }