Update README.md

Author: dkm

README.md

@@ -12,7 +12,7 @@ the docker images used to build the various GCC cross-compilers used on the site
 - check it builds correctly:
   `./ct-ng build`
 - copy the config in this repository in `build/latest` following the naming convention.
-- use `local_build.sh` to build it within the docker container
+- use `local_build.sh` to test a build it within the docker container
   `./local_build.sh arm64 13.2.0`
 - add ct-ng config and commit (and open a Pull Request)