Wording change: New up a specific type, rather than just object

In algorithms that mint MLActivations and MLOperands, construct
the actual type not a generic "object". Also, use Infra wording
around optional paramters to those algorithms.

For #450

index.bs

@@ -898,18 +898,18 @@ The {{MLActivation}} objects (including the ones passed as input to methods) are
 
 <details open algorithm>
   <summary>
-    To <dfn>create an MLActivation</dfn> given |builder|, |name|, |options| and |init-steps|, run the following steps:
+    To <dfn>create an MLActivation</dfn> given |builder|, |name|, optional |options| and optional |init-steps|, run the following steps:
   </summary>
   <div class=algorithm-steps>
-    1. Let |activation| be a new [=object=].
+    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 an [=object=], set |activation|.{{MLActivation/[[options]]}} to |options|.
+    1. If |options| is given, set |activation|.{{MLActivation/[[options]]}} to |options|.
     1. If any of the following sub-steps fail, [=exception/throw=] an "{{OperationError}}" {{DOMException}}.
         1. Make a request to the underlying platform to:
             1. Create an [=implementation-defined=] platform operator |opImpl| for the given |name| operation.
             1. Set |activation|.{{MLActivation/[[operator]]}} to |opImpl|.
-        1. If |init-steps| are defined, run |init-steps| with |options|.
+        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|.
   </div>
@@ -6187,7 +6187,7 @@ The {{MLOperand}} objects are created by the methods of {{MLGraphBuilder}}, inte
   <div class=algorithm-steps>
     1. [=Assert=]: the type of |builder| is {{MLGraphBuilder}}.
     1. [=Assert=]: the type of |desc| is {{MLOperandDescriptor}}.
-    1. Let |operand| be a new [=object=].
+    1. Let |operand| be a new {{MLOperand}}.
     1. Set |operand|.{{MLOperand/[[builder]]}} to |builder|.
     1. Set |operand|.{{MLOperand/[[descriptor]]}} to |desc|.
     1. Return |operand|.
@@ -6200,7 +6200,7 @@ The {{MLOperand}} objects are created by the methods of {{MLGraphBuilder}}, inte
   </summary>
   <div class=algorithm-steps>
     1. [=Assert=]: the type of |operand| is {{MLOperand}}.
-    1. Let |result| be a new [=object=].
+    1. Let |result| be a new {{MLOperand}}.
     1. Set |result|.{{MLOperand/[[builder]]}} to |operand|.{{MLOperand/[[builder]]}}.
     1. Set |result|.{{MLOperand/[[descriptor]]}} to |operand|.{{MLOperand/[[descriptor]]}}.
     1. If |operand|.{{MLOperand/[[name]]}} [=map/exists=], then set |result|.{{MLOperand/[[name]]}} to |operand|.{{MLOperand/[[name]]}}.