add doc/references.txt for Linux tracing related links

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@gmail.com>
add load target in Makefile: make load

"make load" will rmmod and insmod ktapvm

also update README.md

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@gmail.com>