Doc (API): minor aesthetic fix

lib/algo/algo.mli

-(* Time-stamp: <modified the 13/10/2020 (at 15:30) by Erwan Jahier> *)
+(* Time-stamp: <modified the 04/11/2020 (at 08:15) by Erwan Jahier> *)
 (** {1 The Algorithm programming Interface} 
 
     A SASA process is an instance of an algorithm defined via this
@@ -120,8 +120,6 @@ val diameter : unit -> int
    using graph attributes. This function allows one the get their
    values. *)
 val get_graph_attribute : string -> string
-
-
                       
 (** {2 Code Registration}
 
@@ -192,13 +190,14 @@ val register : 's to_register -> unit
      {[
         let potential_function = None (** Mandatory with --worst-daemon (-wd) *);
         let legitimate_function = None (** if different from silent ones *);
-        let fault_function = None (** called when a legitimate configuration is reached *) 
+        let fault_function = None (** called when a legitimate configuration is 
+                                      reached *) 
      ]}
      
     (3) All the algos mentioned in the dot file should define the following functions:
      {[
-       let (init_state: int -> string -> State.t) = finishme 
-       let (enable_f: State.t neighbor list -> State.t -> action list) = finishme
-       let (step_f : State.t neighbor list -> State.t -> action -> State.t ) = finishme
+       let (init_state: int -> string -> State.t) = xxx finishme 
+       let (enable_f: State.t neighbor list -> State.t -> action list) = xxx
+       let (step_f : State.t neighbor list -> State.t -> action -> State.t) = xxx
      ]}
 *)