completion: add parallel download option to _xbps

Author: mmdbalkhi

data/_xbps

@@ -143,7 +143,8 @@ _xbps_install() {
 		{-U,--unpack-only}'[Unpack packages without configuring]' \
 		{-M,--memory-sync}'[Keep remote repository data in memory only]' \
 		{-n,--dry-run}'[Dry-run mode]' \
-		'*'{-R,--repository=-}'[Add repository to the top of the list]:repository url:_files -/' \
+        {-p,--parallel-download=-}'[Number of parallel downloads]:jobs:(1 2 3 4 5 6 8 12 16)' \
+        '*'{-R,--repository=-}'[Add repository to the top of the list]:repository url:_files -/' \
 		{-S,--sync}'[Sync remote repository index]' \
 		--reproducible'[Enable reproducible mode in pkgdb]' \
 		--staging'[Enable use of staged packages]' \