[zh_CN] done /zh/development/sessions.rst
[zh_CN] done /zh/plugins.rst
update deprecated example
Revert b4800b021e18f83f3e73f9f279c6ee53af9129e4 as it breaks the build process.
Merge pull request #2077 from blackpuppy/zh

[zh_CN] done /zh/development/sessions.rst and /zh/plugins.rst
Update docs for cakephp/cakephp#5310