CPT templates

[elzadj]

For ACF project, and maybe something universal.

maxi-blocks/maxi-blocks#5587

[elzadj]

I'm not sure if it's wise to add some fixed CPT templates, because they are custom-made by users, and it's impossible to predict any fields that users create. 99% that our CPT is not going to work for that particular site's needs, and we end up adding redundant templates.