make package error

[NHZlX]

the
$ make
$ make install
is good

but there is error when runing make package
log is :
make: *** No rule to make target package'. Stop.`

[nihui]

library and header files will be installed in build/install dir
not necessary to execute make package

[NHZlX]

the lib compiled on mac is about 200k smaller than cross compiled on android，that's why

[akbarxie]

add Execute permissions to build.sh,just run build.sh,can bulid the project

[zchrissirhcz]

@nihui NHZIX@NHZlX所提到的make package是在wiki页面中提到的，在这里。可以考虑删掉make package这条。。