build plugin failed

I have clone the code to my computer, I follow the step in the doc

but when i compile the code, i got the following error

```
fluent-bit/lib/monkey/include/monkey/mk_core.h:33:10: fatal error: 'mk_core/mk_core_info.h' file not found
#include
^~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.
make[2]: *** [out_stdout2/CMakeFiles/flb-out_stdout2.dir/stdout2.c.o] Error 1
make[1]: *** [out_stdout2/CMakeFiles/flb-out_stdout2.dir/all] Error 2
make: *** [all] Error 2
```

i use the fluent-bit master code