[Fix] `install`: error out when an argument has `---`

Fixes #1915.
diff --git a/nvm.sh b/nvm.sh
index 09538d5..63ab8a9 100644
--- a/nvm.sh
+++ b/nvm.sh
@@ -2520,6 +2520,10 @@
       NVM_UPGRADE_NPM=0
       while [ $# -ne 0 ]; do
         case "$1" in
+          ---*)
+            nvm_err 'arguments with `---` are not supported - this is likely a typo'
+            return 55;
+          ;;
           -s)
             shift # consume "-s"
             nobinary=1