chore: enhance changelog

Author: ulivz

CHANGELOG.md

@@ -4,20 +4,32 @@
 
 ### Bug Fixes
 
-* missing space between italics and bold (close: [#661](https://github.com/vuejs/vuepress/issues/661)) ([7730ee1](https://github.com/vuejs/vuepress/commit/7730ee1))
-* scoped styles of badge component (close: [#653](https://github.com/vuejs/vuepress/issues/653)) ([#657](https://github.com/vuejs/vuepress/issues/657)) ([9b602f2](https://github.com/vuejs/vuepress/commit/9b602f2))
-* set babelrc: false in babel-loader options ([#644](https://github.com/vuejs/vuepress/issues/644)) ([c500201](https://github.com/vuejs/vuepress/commit/c500201))
+* **$seo:** Avoid duplicate `description meta` at runtime. (close: [#665](https://github.com/vuejs/vuepress/issues/665)) ([b207a5f](https://github.com/vuejs/vuepress/commit/b207a5f))
+* **default-theme:** Scoped styles of `Badge` component (close: [#653](https://github.com/vuejs/vuepress/issues/653)) ([#657](https://github.com/vuejs/vuepress/issues/657)) ([9b602f2](https://github.com/vuejs/vuepress/commit/9b602f2))
+* **$build:** set `babelrc: false` in babel-loader options ([#644](https://github.com/vuejs/vuepress/issues/644)) ([c500201](https://github.com/vuejs/vuepress/commit/c500201)) ([@posva](https://github.com/posva))
 * **$build:** exclude dest folder from pageFiles (close: [#654](https://github.com/vuejs/vuepress/issues/654)) ([#655](https://github.com/vuejs/vuepress/issues/655)) ([c1fe692](https://github.com/vuejs/vuepress/commit/c1fe692))
-* **$build:** markdown config should be included in cache identifier ([0ad1a45](https://github.com/vuejs/vuepress/commit/0ad1a45))
-* **$markdown:** cannot highlight external python file (.py) correctly (close: [#660](https://github.com/vuejs/vuepress/issues/660)) ([2a33075](https://github.com/vuejs/vuepress/commit/2a33075))
-* **$seo:** Avoid duplicate description meta at runtime. (close: [#665](https://github.com/vuejs/vuepress/issues/665)) ([b207a5f](https://github.com/vuejs/vuepress/commit/b207a5f))
-
+* **$build:** markdown config should be included in `cache-loader` identifier ([0ad1a45](https://github.com/vuejs/vuepress/commit/0ad1a45))
+* **$markdown:** cannot highlight external python file (`.py`) correctly (close: [#660](https://github.com/vuejs/vuepress/issues/660)) ([2a33075](https://github.com/vuejs/vuepress/commit/2a33075))
+* **$markdown:** missing space between italics and bold (close: [#661](https://github.com/vuejs/vuepress/issues/661)) ([7730ee1](https://github.com/vuejs/vuepress/commit/7730ee1))
+   1. `markdown-it` compiler will intendedly reserve this space between some inline elements, but `preserveWhitespace: false` will remove them. (Ref: [vue-template-compiler#options](https://github.com/vuejs/vue/tree/dev/packages/vue-template-compiler#options))
+   2. **Performance Impact**: Size of whole assets of vuepress documentation:
+      - Before (1952 kb)
+      - After (1960 kb)
 
 ### Features
 
-* transform Badge into async component ([de9a51b](https://github.com/vuejs/vuepress/commit/de9a51b))
 * **$cli:** debug flag at dev mode ([231da6a](https://github.com/vuejs/vuepress/commit/231da6a))
-* **$pwa:** add themeConfig.serviceWorker.updatePopup option (close: [#453](https://github.com/vuejs/vuepress/issues/453)) ([#533](https://github.com/vuejs/vuepress/issues/533)) ([14dbd1e](https://github.com/vuejs/vuepress/commit/14dbd1e))
+* **$default-theme:** transform `Badge` into async component ([de9a51b](https://github.com/vuejs/vuepress/commit/de9a51b))
+* **$default-theme:** **PWA**: themeConfig.serviceWorker.updatePopup option (close: [#453](https://github.com/vuejs/vuepress/issues/453)) ([#533](https://github.com/vuejs/vuepress/issues/533)) ([14dbd1e](https://github.com/vuejs/vuepress/commit/14dbd1e))
+   ``` js
+   module.exports = {
+     themeConfig: {
+       serviceWorker: {
+         updatePopup: true
+       }
+     }
+   }
+   ```