Update Readme_zh-cn.md

line 342 , <p> tag is wrong
Add warning if a data attribute value contains ampersand(s)

Signed-off-by: Timothy Gu <timothygu99@gmail.com>
Merge pull request #1735 from jadejs/ampersand-warn

Add warning if a data attribute value contains ampersand(s)
Merge pull request #1736 from skylerzhang/master

Update Readme_zh-cn.md
Warn about future change to ISO 8601 style dates

See #1062, #1677.

Based on a patch by Forbes Lindesay <forbes@lindesay.co.uk>.

Signed-off-by: Timothy Gu <timothygu99@gmail.com>