Developer-Guide.md: update rootfs build description
Add rootfs distro choices for debian,ubuntu, and suse.
Fixes:
@@ -234,7 +234,7 @@ $ sudo rm -rf ${ROOTFS_DIR}
$ cd $GOPATH/src/github.com/kata-containers/osbuilder/rootfs-builder
$ script -fec 'sudo -E GOPATH=$GOPATH USE_DOCKER=true SECCOMP=no ./rootfs.sh ${distro}'
```
-You MUST choose one of `alpine`, `centos`, `clearlinux`, `euleros`, and `fedora` for `${distro}`. By default `seccomp` packages are not included in the rootfs image. Set `SECCOMP` to `yes` to include them.
+You MUST choose one of `alpine`, `centos`, `clearlinux`, `debian`, `euleros`, `fedora`, `suse`, and `ubuntu` for `${distro}`. By default `seccomp` packages are not included in the rootfs image. Set `SECCOMP` to `yes` to include them.
> **Note:**
>
