chore(gatsby-plugin-manifest): add pluginOptionsSchema (#27421)

* chore(gatsby-plugin-manifest): add pluginOptionsSchema

* Add documentation for localize option

Author: mxstbr

packages/gatsby-plugin-manifest/src/gatsby-node.js

@@ -58,8 +58,49 @@ async function checkCache(cache, icon, srcIcon, srcIconDigest, callback) {
   }
 }
 
+if (process.env.GATSBY_EXPERIMENTAL_PLUGIN_OPTION_VALIDATION) {
+  exports.pluginOptionsSchema = ({ Joi }) => {
+    Joi.object({
+      name: Joi.string(),
+      short_name: Joi.string(),
+      description: Joi.string(),
+      lang: Joi.string(),
+      localize: Joi.array().items(
+        Joi.object({
+          start_url: Joi.string(),
+          name: Joi.string(),
+          short_name: Joi.string(),
+          description: Joi.string(),
+          lang: Joi.string(),
+        })
+      ),
+      start_url: Joi.string(),
+      background_color: Joi.string(),
+      theme_color: Joi.string(),
+      display: Joi.string(),
+      legacy: Joi.boolean(),
+      include_favicon: Joi.boolean(),
+      icon: Joi.string(),
+      theme_color_in_head: Joi.boolean(),
+      crossOrigin: Joi.string().valid(`use-credentials`, `anonymous`),
+      cache_busting_mode: Joi.string().valid(`query`, `name`, `none`),
+      icons: Joi.array().items(
+        Joi.object({
+          src: Joi.string(),
+          sizes: Joi.string(),
+          type: Joi.string(),
+        })
+      ),
+      icon_options: Joi.object({
+        purpose: Joi.string(),
+      }),
+    })
+  }
+}
+
 /**
  * Setup pluginOption defaults
+ * TODO: Remove once pluginOptionsSchema is stable
  */
 exports.onPreInit = (_, pluginOptions) => {
   pluginOptions.cache_busting_mode = pluginOptions.cache_busting_mode ?? `query`