Use related path in our docs for imgs, previous
can not use because website need the absolute path
from root directory, and after we merged
apache/dolphinscheduler-website#789 we have covert
function to do that

close: #9426

* [doc] Add some dev missing doc

Including general-setting, task-definition, audit-log
and they related img

* Change base on suggestion
Co-authored-by: NTq <tianqitobethefirst@gmail.com>