Improved docs on EventLogger

Unfortunately, since Swift dropped named arguments on closures, Xcode provides no clues as to what they are.
All you can see when opening the compiled framework on Xcode is:
```swift
/// A type that represents an event logging function.
public typealias EventLogger = (String, String, String, String, Int) -> Swift.Void
```

So hopefully this will make it a bit easier to use.

Author: NachoSoto

Sources/EventLogger.swift

@@ -32,6 +32,12 @@ private func defaultEventLog(identifier: String, event: String, fileName: String
 }
 
 /// A type that represents an event logging function.
+/// Signature is:
+///		- identifier 
+///		- event
+///		- fileName
+///		- functionName
+///		- lineNumber
 public typealias EventLogger = (
 	_ identifier: String,
 	_ event: String,