Intuition on samplers and optimisers

[DavAug]

I was just discussing with @ben18785 that it may be beneficial to make the sampling and optimisation methods more accessible by providing some intuition on the algorithms in the docstrings (just a couple lines of code, and for the in-depth understanding we typically have references to the original paper).

I personally am hesitant to use methods which I don't really understand and if other users feel the same way this little intuition section might encourage more users to explore different samplers than ACMC or HMC.