update build script if main then change to latest

.gitignore

@@ -1,2 +1,4 @@
 sshkeys/clients/
 sshkeys/host/
+crontab.txt
+maintain_repo.sh

build.sh

@@ -24,6 +24,10 @@ build_docker_image() {
   docker build -t "$DOCKER_IMAGE_NAME:$TAG" .
 }
 
+if [ "$GIT_BRANCH" == "main" ]; then
+  GIT_BRANCH="latest"
+fi
+
 case "$1" in
   run)
     run_docker_container