Extend bash completion to cover new flags

Ensure the new flags added to `manifest add` are known to bash
completion.

Signed-off-by: Flavio Castelli <fcastelli@suse.com>

completions/bash/podman

@@ -1846,6 +1846,9 @@ _podman_manifest() {
 _podman_manifest_add() {
 	 local options_with_args="
      --annotation
+     --authfile
+     --cert-dir
+     --creds
      --arch
      --features
      --os
@@ -1857,6 +1860,7 @@ _podman_manifest_add() {
      --all
      --help
      -h
+     --tls-verify
      "
 
      _complete_ "$options_with_args" "$boolean_options"