annotate Swagger JSON with OpenRiskNet (x-orn) annotation

As in:

```json
{
"swagger": "2.0",
"info": {
"version": "0.9.0",
"title": "BridgeDb webservices",
"x-orn-@id": "http://webservice.bridgedb.org",
"x-orn-@type": "x-orn:Service"
},
"consumes":["text/html"],
"produces":["*/*"],
"host": "webservice.bridgedb.org",
"schemes": [
"http",
"https"
],
"paths": {
"/{organism}/xrefs/{systemCode}/{identifier}": {
"get": {
"x-orn-@type": "x-orn:Identifier",
"x-orn:path": "http://webservice.bridgedb.org/{organism}/xrefs/{systemCode}/{identifier}",
"x-orn:method": "Post",
"description": "Returns a list of xrefs that map to a given identifier, data source, and organism.",
"tags":["Genes"],
```

Locate the repository's Swagger JSON and compare its service and operation entries with the x-orn annotation example in the issue. Determine which entries need OpenRiskNet metadata, add the requested annotations, and validate that the resulting document remains valid Swagger JSON.

Written by the indexing model from the issue text.