Add about endpoint

ansys/api/additive/VERSION

@@ -1 +1 @@
-1.2.2
+1.2.3

ansys/api/additive/v0/about.proto

@@ -0,0 +1,21 @@
+syntax = "proto3";
+
+package ansys.api.additive.v0.about;
+
+option csharp_namespace = "Ansys.Api.Additive";
+import "google/api/annotations.proto";
+import "google/protobuf/empty.proto";
+
+
+// The greeting service definition.
+service About {
+  rpc About (google.protobuf.Empty) returns (AboutReply) {
+    option (google.api.http) = {
+      get: "/about"
+    };
+  }
+}
+
+message AboutReply {
+    map<string, string> metadata = 1;
+}

google/api/annotations.proto

@@ -0,0 +1,31 @@
+// Copyright (c) 2015, Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+syntax = "proto3";
+
+package google.api;
+
+import "google/api/http.proto";
+import "google/protobuf/descriptor.proto";
+
+option go_package = "google.golang.org/genproto/googleapis/api/annotations;annotations";
+option java_multiple_files = true;
+option java_outer_classname = "AnnotationsProto";
+option java_package = "com.google.api";
+option objc_class_prefix = "GAPI";
+
+extend google.protobuf.MethodOptions {
+  // See `HttpRule`.
+  HttpRule http = 72295728;
+}