fix: prefer webmanifest extension over json

https://w3c.github.io/manifest/#media-type-registration

src/meta/tags.js

@@ -55,7 +55,7 @@ Tags.parse = async (req, data, meta, link) => {
 		href: nconf.get('relative_path') + nconf.get('upload_url') + '/system/favicon.ico' + (Meta.config['cache-buster'] ? '?' + Meta.config['cache-buster'] : ''),
 	}, {
 		rel: 'manifest',
-		href: nconf.get('relative_path') + '/manifest.json',
+		href: nconf.get('relative_path') + '/manifest.webmanifest',
 	}];
 
 	if (plugins.hasListeners('filter:search.query')) {

src/routes/meta.js

@@ -6,7 +6,7 @@ module.exports = function (app, middleware, controllers) {
 	app.get('/sitemap/categories.xml', controllers.sitemap.getCategories);
 	app.get(/\/sitemap\/topics\.(\d+)\.xml/, controllers.sitemap.getTopicPage);
 	app.get('/robots.txt', controllers.robots);
-	app.get('/manifest.json', controllers.manifest);
+	app.get('/manifest.webmanifest', controllers.manifest);
 	app.get('/css/previews/:theme', controllers.admin.themes.get);
 	app.get('/osd.xml', controllers.osd.handle);
 };