Move all config.inc.php to data directory

[huan]

Currently, some config is in our GitHub repository and it includes some sensitive data.

We should move those files to our data/ directory, which is in the volume outside of the container.

Checklist

• https://github.com/zixia/17salsa.com/blob/main/www/ask/config.inc.php
• https://github.com/zixia/17salsa.com/blob/main/www/home/config.php
• https://github.com/zixia/17salsa.com/blob/main/www/site/config.php
• https://github.com/zixia/17salsa.com/blob/main/www/vip/config.inc.php
• https://github.com/zixia/17salsa.com/blob/main/www/wiki/config.php (it's ok because it's clean)