chore(v2): changelog and docs nits

Author: endiliey

CHANGELOG-2.x.md

@@ -1,6 +1,6 @@
 # Docusaurus 2 Changelog
 
-## Unreleased
+## 2.0.0-alpha.27
 
 - Add `@theme/Tabs` which can be used to implement multi-language code tabs.
 - Implement `custom_edit_url` and `hide_title` markdown header for docusaurus v1 feature parity.

website/docs/migrating-from-v1-to-v2.md

@@ -37,8 +37,8 @@ Meanwhile, the default doc site functionalities provided by Docusaurus 1 are now
 {
   dependencies: {
 -    "docusaurus": "^1.x.x",
-+    "@docusaurus/core": "^2.0.0-alpha.26",
-+    "@docusaurus/preset-classic": "^2.0.0-alpha.26",
++    "@docusaurus/core": "^2.0.0-alpha.27",
++    "@docusaurus/preset-classic": "^2.0.0-alpha.27",
   }
 }
 ```
@@ -71,8 +71,8 @@ A typical Docusaurus 2 `package.json` may look like this:
     "deploy": "docusaurus deploy"
   },
   "dependencies": {
-    "@docusaurus/core": "^2.0.0-alpha.26",
-    "@docusaurus/preset-classic": "^2.0.0-alpha.26",
+    "@docusaurus/core": "^2.0.0-alpha.27",
+    "@docusaurus/preset-classic": "^2.0.0-alpha.27",
     "classnames": "^2.2.6",
     "react": "^16.10.2",
     "react-dom": "^16.10.2"