chore: added docs to test suite

Author: JeneaVranceanu

Tests/web3swiftTests/localTests/BIP39StringTests.swift

@@ -9,7 +9,8 @@ import XCTest
 @testable import Web3Core
 @testable import web3swift
 
-
+/// This test suite is focused on testing the ability of `BIP32Keystore`
+/// to be able to parse and work with mnemonic phrase that is of type `String`.
 final class BIP39StringTests: XCTestCase {
 
     let mnemonic = "fruit wave dwarf banana earth journey tattoo true farm silk olive fence"