feat: don't force me to play find the difference in a PR page

[kumachan-mis]

I don't want find the difference. The extension should solve the problem.

e.g. we have the following puml code in the base branch:

@startuml
class C {
  field: float
  needlessField: int
  int method(arg: float)
}
@enduml

and the following one in the pr branch:

@startuml
class C {
  field: float
  newField: int
  int method(arg: float)
}
@enduml

newField: int needs to be visualized in green and needlessField: int needs to be visualized in red