Does that development module fit easily on a common “wireless breadboard”? If so, (and I suspect it does.) the pin spacings are some integer multiple of 0.1 inch (2.54mm). That should be all the information you need to draft a usable footprint. (From the photos, my eyeball estimate is 0.7" (17.78mm) between rows, but that is an unusual value so I bet it’s either 0.6" (15.24mm) or 0.8" (20.32mm).)
Do you intend to use the mounting holes in that module? (Given the apparent size and mass of the module it certainly won’t hurt to anchor it with at least screws in diagonally opposite corners.) Even if your project won’t use the mounting screws, mating holes should appear on your footprint for completeness, and for your benefit the next time you use the part and want to fasten it down. Unlike the electrical footprint, the mounting holes could be on either a metric, or imperial, grid pattern.
Fundamental question: Why are you using components whose manufacturer doesn’t supply even a basic mechanical outline drawing? I have encountered that practice in the Arduino world where supposedly interchangeable modules don’t have compatible mechanical interfaces. If the supplier won’t adequately describe (with drawings and sketches) the components he is selling to you, it will cost you money, schedule time, and frustration in the long run.