Major 2.0 (#20)

* New 2.0 version + DependencyInjection library

* Updated docs and repo settings (devcontainers, vscode, github, etc.)

* Added tests

* Fixed bugs

* Minor test project refactoring

* Updated projects
- Added symbol packages
- Updated package versions to pre-release

* Updated SECURITY.md

* Added GitHub Actions workflows

libraries/SimpleOTP.DependencyInjection/IOtpService.cs

@@ -0,0 +1,33 @@
+namespace SimpleOTP.DependencyInjection;
+
+/// <summary>
+/// Provides methods for generating and validating One-Time Passwords.
+/// </summary>
+public interface IOtpService
+{
+	/// <summary>
+	/// Creates an OTP URI for specified user and secret.
+	/// </summary>
+	/// <param name="username">The username of the user.</param>
+	/// <param name="secret">The secret to use.</param>
+	/// <param name="counter">(only for HOTP) The counter to use.</param>
+	/// <returns>The generated URI.</returns>
+	public Uri CreateUri(string username, OtpSecret secret, long counter = 0);
+
+	/// <summary>
+	/// Creates an OTP code for specified user and secret.
+	/// </summary>
+	/// <param name="secret">The secret to use.</param>
+	/// <param name="counter">(only for HOTP) The counter to use.</param>
+	public OtpCode GenerateCode(OtpSecret secret, long counter = 0);
+
+	/// <summary>
+	/// Validates an OTP code for specified user and secret.
+	/// </summary>
+	/// <param name="code">The code to validate.</param>
+	/// <param name="secret">The secret to use.</param>
+	/// <param name="resyncValue">The resync value. Shows how much the code is ahead or behind the current counter value.</param>
+	/// <param name="counter">(only for HOTP) The counter to use.</param>
+	/// <returns><c>true</c> if the code is valid; otherwise, <c>false</c>.</returns>
+	public bool ValidateCode(OtpCode code, OtpSecret secret, out int resyncValue, long counter = 0);
+}