update genman script to also perform build

Author: d99kris

genman.sh

@@ -1,3 +1,4 @@
 #!/bin/bash
 
-cd src && help2man -n "measure stack usage in applications" -N -o stackusage.1 ./stackusage
+mkdir -p build && cd build && cmake .. && make -s && \
+help2man -n "measure stack usage in applications" -N -o stackusage.1 ./stackusage