I am reading unreal docs (Unreal Editor Manual) for quite a while already and to my regret the quality of the docs is low. First and foremost problem is not all sections are linked directly from the documentation tree! That is, some sections are hanging separately and I find them occasionally mostly via google or searching on the site itself.
Next, explanations in some reference-like sections (e.g. describing some details panels) are not covering all properties and sometimes explain the property in one sentence or so. Deeper explanations with pictures are often required. Sometimes name of the property is given without the explanation of where the property in the editor is located.
And last, separation of some subsections is strange… Whole pages are dedicated to couple of paragraphs without a lot of useful information. Either put more details or merge subsections.
All in all documentation could be done better and I hope this will be addressed in the future