doc: Add description for detach_kprobe/detach_kretprobe
doc: Add description for detach_kprobe/detach_kretprobe

Add missing descriptions for detach_kprobe and detach_kretprobe.

Signed-off-by: Hao Lee <c1898eb4f221961a4c9924db8ec6101df4396ac5@didiglobal.com>

brendangregg/bcc,brendangregg/bcc,iovisor/bcc,brendangregg/bcc,brendangregg/bcc,iovisor/bcc,iovisor/bcc,iovisor/bcc,iovisor/bcc,brendangregg/bcc