Fix typos in README (#546)

Motivation:

Parts of the README were outdated and incorrect.

Modifications:

Update the README to correct known typographic errors. Update the
section on TLS since it was incorrect.

Removed old TLS code the README referred to but could not be used.

Result:

More helpful README

README.md

@@ -205,11 +205,12 @@ logical cores on your system.
 We also `wait` for the server to start before setting up a client.
 
 ```swift
-let serverEventLoopGroup = PlatformSupport.makeEventLoopGroup(numberOfThreads: 1)
+let serverEventLoopGroup = PlatformSupport.makeEventLoopGroup(loopCount: 1)
 let configuration = Server.Configuration(
-  target: .hostAndPort(address, port),
+  target: .hostAndPort(host, port),
   eventLoopGroup: serverEventLoopGroup,
-  serviceProviders: [EchoProvider()])
+  serviceProviders: [EchoProvider()]
+)
 
 let server = try Server.start(configuration: configuration).wait()
 ```
@@ -337,7 +338,8 @@ let anyService = AnyServiceClient(connection: connection)
 let get = anyService.makeUnaryCall(
   path: "/echo.Echo/Get",
   request: Echo_EchoRequest.with { $0.text = "Hello!" },
-  responseType: Echo_EchoResponse.self)
+  responseType: Echo_EchoResponse.self
+)
 ```
 
 Calls for client-, server- and bidirectional-streaming are done in a similar way
@@ -363,8 +365,9 @@ trailing metadata, and status. _Unary response_ calls also have a future for the
 response whilst _streaming response_ calls will call a handler for each response.
 Calls with _unary requests_ send their message when instantiating the call,
 _streaming request_ calls include methods on the call object to send messages
-(`sendMessage(_:flush:)` and `sendMessage(_:promise:flush:)`) as well as methods
-for terminated the stream of messages (`sendEnd()` and `sendEnd(promise:)`).
+(`sendMessage(_:)`, `sendMessages(_:)`, `sendMessage(_:promise:)`,
+`sendMessages(_:promise:)`) as well as methods for terminating the stream of
+messages (`sendEnd()` and `sendEnd(promise:)`).
 
 These differences are summarised in the following table.
 
@@ -378,35 +381,31 @@ These differences are summarised in the following table.
 ### Using TLS
 
 gRPC calls can be made over a secure channel by configuring TLS. This requires
-specifying `tlsConfiguration` on `ClientConnection.Configuration` or
+specifying `tls` on `ClientConnection.Configuration` or
 `Server.Configuration`.
 
-Configuring TLS requires a [`NIOSSLContext`][nio-ref-sslcontext] which in turn
-requires a [`TLSConfiguration`][nio-ref-tlsconfig] (this is _not_ the same as
-`ClientConnection.TLSConfiguration` or `Server.TLSConfiguration`).
-
-For the client, [`TLSConfiguration`][nio-ref-tlsconfig] can be as simple as:
+For the client, `tls` can be as simple as:
 
 ```swift
-let configuration = TLSConfiguration.forClient(
-  minimumTLSVersion: TLSVersion = .tlsv12,
-  applicationProtocols: GRPCApplicationProtocolIdentifier.allCases.map { $0.rawValue }
-)
+let tls = ClientConnection.Configuration.TLS()
 ```
 
-For the server, [`TLSConfiguration`][nio-ref-tlsconfig] is slightly more
-complicated as it requires a certificate chain and private key:
+For the server, `tls` is slightly more complicated as it requires a certificate
+chain and private key:
 
 ```swift
-let configuration = TLSConfiguration.forServer(
-  certificateChain: [.file("cert.pem")],
-  privateKey: .file("key.pem"),
-  minimumTLSVersion: TLSVersion = .tlsv12,
-  applicationProtocols: GRPCApplicationProtocolIdentifier.allCases.map { $0.rawValue }
+# Load the certificates from "cert.pem"
+let certificates: [NIOSSLCertificate] = try NIOSSLCertificate.fromPEMFile("cert.pem")
+
+let tls = Server.Configuration.TLS(
+  certificateChain: certificates.map { .certificate($0) },
+  privateKey: .file("key.pem")
 )
 ```
 
-Note that the gRPC specification requires TLS v1.2 or later.
+The `TLS` configuration is a subset of [`TLSConfiguration`][nio-ref-tlsconfig]
+provided by `NIOSSL` to ensure it meets the gRPC specification. Users may also
+initialize `TLS` with `TLSConfiguration` should they require.
 
 ### NIO vs. NIO Transport Services
 
@@ -465,7 +464,6 @@ Please get involved! See our [guidelines for contributing](CONTRIBUTING.md).
 [network-framework]: https://developer.apple.com/documentation/network
 [nio-ref-elf]: https://apple.github.io/swift-nio/docs/current/NIO/Classes/EventLoopFuture.html
 [nio-ref-elg]: https://apple.github.io/swift-nio/docs/current/NIO/Protocols/EventLoopGroup.html
-[nio-ref-sslcontext]: https://apple.github.io/swift-nio-ssl/docs/current/NIOSSL/Classes/NIOSSLContext.html
 [nio-ref-tlsconfig]: https://apple.github.io/swift-nio-ssl/docs/current/NIOSSL/Structs/TLSConfiguration.html
 [nio-ts]: https://github.com/apple/swift-nio-transport-services
 [protobuf-releases]: https://github.com/protocolbuffers/protobuf/releases

Sources/GRPC/Server.swift

@@ -210,16 +210,6 @@ extension Server {
       self.tls = tls
     }
   }
-
-  /// The TLS configuration for a connection.
-  public struct TLSConfiguration {
-    /// The SSL context to use.
-    public var sslContext: NIOSSLContext
-
-    public init(sslContext: NIOSSLContext) {
-      self.sslContext = sslContext
-    }
-  }
 }
 
 fileprivate extension Server.Configuration {