Merge branch 'dl/complete-submodule-absorbgitdirs'

Command-line completion (in contrib/) learned to tab-complete the
"git submodule absorbgitdirs" subcommand.

* dl/complete-submodule-absorbgitdirs:
  completion: complete git submodule absorbgitdirs

contrib/completion/git-completion.bash

@@ -2573,7 +2573,7 @@ _git_submodule ()
 {
 	__git_has_doubledash && return
 
-	local subcommands="add status init deinit update summary foreach sync"
+	local subcommands="add status init deinit update summary foreach sync absorbgitdirs"
 	local subcommand="$(__git_find_on_cmdline "$subcommands")"
 	if [ -z "$subcommand" ]; then
 		case "$cur" in