Add <yaml[<id>].read[<path>].as_list>

With <yaml.read>, Yaml 'lists' will return "[item1, item2, item3]".
This tag allows the list to be turned into a dList: li@item1|item2|item3
Add optional split_list to split dList values in Yaml command

This allows you to do
- yaml write:MyKey.SubkeyList value:li@item1|item2|item3 split_list
which will then save as
MyKey:
SubkeyList:
- item1
- item2
- item3