Fix bug: forgot a "/" in COPY directive

.devcontainer/Dockerfile

@@ -12,7 +12,7 @@ ENV USERNAME $USERNAME
 ENV USER_UID $USER_UID
 ENV USER_GID ${USER_UID}
 
-COPY library-script/*.sh /tmp/library-script
+COPY library-script/*.sh /tmp/library-script/
 
 RUN yum update -y && \
     sh /tmp/library-script/setup.sh && \