Apply suggestions from code review

Co-authored-by: Xianda Sun <[email protected]>

Author: torfjelde

docs/src/api.md

@@ -133,11 +133,8 @@ end
 To implement the state, we need to keep track of a couple of things:
 - `index`: the index of the sampler used in this `step`.
 - `states`: the current states of _all_ the components.
-Two aspects of this might seem a bit strange:
-1. We need to keep track of the states of _all_ components rather than just the state for the sampler we used previously.
-2. We need to put the `transition` from the `step` into the state.
-
-The reason for (1) is that lots of samplers keep track of more than just the previous realizations of the variables, e.g. in `AdvancedHMC.jl` we keep track of the momentum used, the metric used, etc.
+We need to keep track of the states of _all_ components rather than just the state for the sampler we used previously.
+The reason is that lots of samplers keep track of more than just the previous realizations of the variables, e.g. in `AdvancedHMC.jl` we keep track of the momentum used, the metric used, etc.
 
 For (2) the reason is similar: some samplers might keep track of the variables _in the state_ differently, e.g. you might have a sampler which is _independent_ of the current realizations and the state is simply `nothing`.