chore: fix code snippet typo (missing semi-colon) (#658)

Curtis Belt · ulivz · commit 459a2c1953ff · 2018-07-19T13:48:37.000+08:00
diff --git a/docs/default-theme-config/README.md b/docs/default-theme-config/README.md
@@ -374,7 +374,7 @@ But the `refresh` button activates the new service worker immediately.
 ``` js
 module.exports = {
   themeConfig: {
-    serviceWorker {
+    serviceWorker: {
       updatePopup: true | {message: "New content is available.", buttonText: "Refresh"}
     }
   }

Original file line number	Diff line number	Diff line change
@@ -374,7 +374,7 @@ But the `refresh` button activates the new service worker immediately.
`374`	`374`	``` js
`375`	`375`	`module.exports = {`
`376`	`376`	`themeConfig: {`
`377`		`- serviceWorker {`
	`377`	`+ serviceWorker: {`
`378`	`378`	`updatePopup: true \| {message: "New content is available.", buttonText: "Refresh"}`
`379`	`379`	`}`
`380`	`380`	`}`