docs: add version info in playground.html

bin/build-docs.sh

@@ -2,25 +2,13 @@
 
 ./bin/build-contributors.sh
 ./bin/build-apidoc.sh
+./bin/build-changelog.sh
 
 cd docs
 npm ci
 npm run build
 cp CNAME public/
 
-cp ../CHANGELOG.md source/tutorials/changelog.md
-sed -i \
-  -e 's/{%/{% raw %}{%{% endraw %}/g' \
-  -e 's/{{/{% raw %}{{{% endraw %}/g' \
-  -e '1 s/"/\"/g' \
-  -e '1 s/</\&lt;/g' \
-  -e '1 s/>/\&gt;/g' \
-  source/tutorials/changelog.md
-cp source/tutorials/changelog.md source/zh-cn/tutorials/changelog.md
-
-sed -i '1i ---\ntitle: Changelog\nauto: true\n---\n' source/tutorials/changelog.md
-sed -i '1i ---\ntitle: 更新日志\nauto: true\n---\n' source/zh-cn/tutorials/changelog.md
-
 if [ "$HEXO_ALGOLIA_INDEXING_KEY" != "" ]; then
     npm run index
 fi