Adding Mapper's comments inside the editor for specific decisions

[hi-mei]

Usually its quite annoying to explain the same stuff for different people when they ask you (mapper) about specific decision, so instead it would me break to have some kind of layer of comments for specific patterns etc, so people (other modders and mappers) could understand why did you do this or that without wasting time of huge discussions. New mapeprs could also learn faster using that feature.

Proposal designs of the feature:
It can look like that: