docs: add documentation for manifestCrossorigin (#5571) [ci skip]

Author: haoqunjiang

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

@@ -84,6 +84,12 @@ file, or the `"vue"` field in `package.json`.
       - display: `'standalone'`
       - theme_color: `pwa.themeColor`
 
+- **pwa.manifestCrossorigin**
+
+  - Default: `undefined`
+
+    Value for `crossorigin` attribute in manifest link tag in the generated HTML. You may need to set this if your PWA is behind an authenticated proxy. See [cross-origin values](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/link#attr-crossorigin) for more details.
+
 - **pwa.iconPaths**
 
   - Defaults:

packages/@vue/cli-ui/locales/en.json

@@ -720,7 +720,7 @@
             },
             "manifestCrossorigin": {
               "message": "Attribute value for manifest.json link tag's crossorigin attribute",
-              "description": "Value for `crossoriging` attribute in manifest link tag in the generated HTML, you may need to set this if your pwa is behind an authenticated proxy"
+              "description": "Value for `crossorigin` attribute in manifest link tag in the generated HTML, you may need to set this if your pwa is behind an authenticated proxy"
             }
           }
         },