feat: add ability to deploy process types in parallel

plugins/scheduler-docker-local/subcommands/set

@@ -9,13 +9,13 @@ cmd-scheduler-docker-local-set() {
   declare cmd="scheduler-docker-local:set"
   [[ "$1" == "$cmd" ]] && shift 1
   declare APP="$1" KEY="$2" VALUE="$3"
-  local VALID_KEYS=("disable-chown")
+  local VALID_KEYS=("disable-chown" "parallel-schedule-count")
   verify_app_name "$APP"
 
   [[ -z "$KEY" ]] && dokku_log_fail "No key specified"
 
   if ! fn-in-array "$KEY" "${VALID_KEYS[@]}"; then
-    dokku_log_fail "Invalid key specified, valid keys include: disable-chown"
+    dokku_log_fail "Invalid key specified, valid keys include: disable-chown, parallel-schedule-count"
   fi
 
   if [[ -n "$VALUE" ]]; then