Renamed the WebsiteCore target in the Website service package as WebsiteLibrary. (#14)

This PR contains the work done to rename the _Website_ service's library SwiftPM target from `WebsiteCore` to `WebsiteLibrary`, updating every reference across the manifest, source, tests, Xcode schemes, and documentations.

Reviewed-on: rock-n-code/loud-amsterdam#14
Co-authored-by: Javier Cicchelli <javier@rock-n-code.com>
Co-committed-by: Javier Cicchelli <javier@rock-n-code.com>

Services/Website/Tests/Library/Cases/Internal/Pages/ErrorPageTests.swift

@@ -2,7 +2,7 @@ import Elementary
 import Foundation
 import Testing
 
-@testable import WebsiteCore
+@testable import WebsiteLibrary
 
 @Suite("ErrorPage page")
 struct ErrorPageTests {

Services/Website/Tests/Library/Cases/Internal/Pages/IndexPageTests.swift

@@ -2,7 +2,7 @@ import Elementary
 import Foundation
 import Testing
 
-@testable import WebsiteCore
+@testable import WebsiteLibrary
 
 @Suite("IndexPage page")
 struct IndexPageTests {