Updated Structure, and fixed paths.

- Project does not work still in this version as communication is still not happening between Client/Server/Core. Fake UI is still somewhat needed to progress

RelayClient/Crypto/KeyStorage.cs

@@ -0,0 +1,20 @@
+namespace RelayClient.Crypto;
+
+public static class KeyStorage
+{
+    public static void SavePrivateKey(string username, string privateKey)
+    {
+        Directory.CreateDirectory("keys");
+        File.WriteAllText(Path.Combine("keys", $"{username}.private.key"), privateKey);
+    }
+
+    public static string LoadPrivateKey(string username)
+    {
+        return File.ReadAllText(Path.Combine("keys", $"{username}.private.key"));
+    }
+
+    public static bool PrivateKeyExists(string username)
+    {
+        return File.Exists(Path.Combine("keys", $"{username}.private.key"));
+    }
+}