Pastes together several CTMCs into one. It doesn't check that the rules of the CTMCs are held to.
combineCTMC(sims)a list each of whose element is a CTMC; so sims[[i]] is a CTMC. sims[[i]] can be of class "CTMC" or a list.
Returns a list (not a CTMC object!) with states, times, and T.
Note that each CTMC should include "0" as its first time. And the last state of sims[[i]] and the first state of sims[[i+1]] should "match" in that the user should check they follow the rules of whatever the generating process is for the CTMC.