Remove obfuscated code

Obfuscated code in plugins is not allowed as per rule 4 in the plugin guidelines:
https://ww.wp.xz.cn/plugins/about/guidelines/

Please replace the obfuscated javascript code for auto indentation with a non-obfuscated version, or your plugin may be removed from the WP.org plugin repository.

https://ww.wp.xz.cn/plugins/tabs-in-post-editor/