[SC2] how adding mass points to a map?

[:1]Well, like the title says, I would like to know how to add mass points to a map.
I can't find it so if you know how to do this please leave a comment.|||Start on page 1 in this forum... Read every topic, it will take a week if you spend like one hour every evening. After that you will find threads about "FAME" with other extreme useful posts and you will also master the save.lua file which is the key of modding the mass spots in SC2 maps.
good luck :)|||Thanks for your comment
I already found the save.lua file, but didn't understand what to do whit it