In addition to MaxQ’s online documentation (here), the Plugin files contain some useful documentation as well.
However, Unreal Engine does not consider the documentation files to be Unreal Engine content “assets”, so they cannot be seen or browsed from the UE Content Browser. You’ll need to use a file browser to access the documentation.
First, make sure you’ve selected “Show Plugin Content” in the Content Browser Settings.
Once the MaxQ Spaceflight Toolkit Content directory is visible, right-click to bring up the context menu and select “Show In Explorer” (Or “Show In Finder”, on MacOS).
This will take you to the MaxQ/Content directory. The MaxQ/Documentation directory immediately follows it.