Remove init-steps from MLActivation creation.

Also, simplify the use of options and operator, aligning with how
MLOperands are created.

index.bs

@@ -1164,9 +1164,6 @@ interface MLActivation {};
     ::
         The {{MLActivation}}'s name.
     : <dfn>\[[builder]]</dfn> of type {{MLGraphBuilder}}
-    ::
-        The graph builder object this {{MLActivation}} belongs to.
-    : <dfn>\[[options]]</dfn> of type [=ordered map=]
     ::
         A dictionary containing {{MLActivation}} options.
     : <dfn>\[[operator]]</dfn> of type [=operator=]
@@ -1186,16 +1183,13 @@ The {{MLActivation}} objects (including the ones passed as input to methods) are
 
 <details open algorithm>
   <summary>
-    To <dfn>create an MLActivation</dfn> given {{MLGraphBuilder}} |builder|, [=string=] |name|, optional [=ordered map=] |options| and optional algorithm |init-steps|, run the following steps:
+    To <dfn>create an MLActivation</dfn> given {{MLGraphBuilder}} |builder|, [=string=] |name| and optional [=ordered map=] |options|, run the following steps:
   </summary>
     1. Let |activation| be a new {{MLActivation}}.
     1. Set |activation|.{{MLActivation/[[builder]]}} to |builder|.
     1. Set |activation|.{{MLActivation/[[name]]}} to |name|.
-    1. If |options| is given, set |activation|.{{MLActivation/[[options]]}} to |options|.
-    1. Let |operator| be an [=operator=] for the |name| operation.
+    1. Let |operator| be an [=operator=] for the |name| operation, given |options|.
     1. Set |activation|.{{MLActivation/[[operator]]}} to |operator|.
-    1. If |init-steps| are given, run |init-steps| with |options|.
-    1. Otherwise, initialize |activation|.{{MLActivation/[[operator]]}} given |options| in an [=implementation-defined=] way for the given |name| operation.
     1. Return |activation|.
 </details>