gausslaguerre(39,44.8) doesn't converge, document these conditions for convergence

[the-noble-argon]

So I found that gausslaguerre(39,44.8) didn't converge but gausslaguerre(100,44.8) did.

I didn't see anywhere in the documentation or the error messaging that convergence is more likely if
(1) We make sure that "n > 2α"
(2) That there is a practical maximum value for "α" at about 50 (at which point you should probably be using gausshermite due to the central limit theorem)
Suggesting this in the documentation or error message might be useful.