README: fixes wrong endpoint name siav2 -> query

README.md

@@ -23,7 +23,7 @@ curl --get http://localhost:8004/vlkb/datasets/availability
 
 - **availability** is a [VOSI](https://ivoa.net/documents/VOSI/20170524/REC-VOSI-1.1.html) end-point and returns information whether the service is active
 - **capabilities** is a [VOSI](https://ivoa.net/documents/VOSI/20170524/REC-VOSI-1.1.html) end-point which describes service' functions and paramters
-- **siav2** synchronous end-point provides [SIAv2](https://ivoa.net/documents/SIA) service; responds with a [VOTable](https://ivoa.net/documents/VOTable/).
+- **query** synchronous end-point provides [SIAv2](https://ivoa.net/documents/SIA) service; responds with a [VOTable](https://ivoa.net/documents/VOTable/).
 
 ## Docker image