Added missing docstrings (#3577)

com.unity.ml-agents/Runtime/Agent.cs

             public int maxStep;
         }
 
+        /// <summary>
+        /// The team ID for this Agent.
+        /// </summary>
         public int TeamId {
             get {
                 LazyInitialize();
+
+        /// <summary>
+        /// The name of the behavior of the Agent.
+        /// </summary>
         public string BehaviorName  {
             get {
                 LazyInitialize();

com.unity.ml-agents/Runtime/Policies/BehaviorParameters.cs

 
     /// <summary>
     /// Defines what type of behavior the Agent will be using
-    /// - Default : The Agent will use the remote process for decision making.
-    /// if unavailable, will use inference and if no model is provided, will use
-    /// the heuristic.
-    /// - HeuristicOnly : The Agent will always use its heuristic
-    /// - InferenceOnly : The Agent will always use inference with the provided
-    /// neural network model.
+        /// <summary>
+        /// The Agent will use the remote process for decision making.
+        /// if unavailable, will use inference and if no model is provided, will use
+        /// the heuristic.
+        /// </summary>
+
+        /// <summary>
+        /// The Agent will always use its heuristic
+        /// </summary>
+
+        /// <summary>
+        /// The Agent will always use inference with the provided
+        /// neural network model.
+        /// </summary>
         InferenceOnly
     }