Update perfect readme (#4060)

* [ci skip] updated readme to include the dbs added to the configurations

* [ci skip] fixed typo

frameworks/Swift/perfect/README.md

@@ -4,8 +4,11 @@ This is the [Perfect](https://www.perfect.org) portion of a [benchmarking test s
 
 ## Variants
 
-There is one version of the benchmark, not using any backend:
+There is are four versions of the benchmark, three of which use databases:
 - `Perfect`: No DB
+- `Perfect-MySQL`: Using MySQL
+- `Perfect-PostgreSQL`: Using PostgreSQL
+- `Perfect-MongoDB`: Using MongoDB
 
 Each listens on port 8080, and use common URLs described below.
 
@@ -14,6 +17,9 @@ Each listens on port 8080, and use common URLs described below.
 This version of the benchmark requires Swift 4.1, and uses the following versions of Perfect and dependencies:
 
 - [Perfect 3.0](https://github.com/PerfectlySoft/Perfect-HTTPServer.git)
+- [Perfect-MySQL 3.0](https://github.com/PerfectlySoft/Perfect-MySQL.git)
+- [Perfect-PostgreSQL 3.0](https://github.com/PerfectlySoft/Perfect-PostgreSQL.git)
+- [Perfect-MongoDB 3.0](https://github.com/PerfectlySoft/Perfect-MongoDB.git)
 
 ## Test URLs
 ### JSON serialization
@@ -23,3 +29,15 @@ http://localhost:8080/json
 ### Plaintext
 
 http://localhost:8080/plaintext
+
+### DB Store - on all configurations
+
+http://localhost:8080/db
+
+### Queries - on all configurations
+
+http://localhost:8080/queries/queries=2
+
+### Updates - on all configurations
+
+http://localhost:8080/updates/queries=2