Restructure solution layout by module

src/__Libraries/StellaOps.Cryptography/SignatureAlgorithms.cs

@@ -0,0 +1,13 @@
+namespace StellaOps.Cryptography;
+
+/// <summary>
+/// Known signature algorithm identifiers.
+/// </summary>
+public static class SignatureAlgorithms
+{
+    public const string Es256 = "ES256";
+    public const string Es384 = "ES384";
+    public const string Es512 = "ES512";
+    public const string Ed25519 = "ED25519";
+    public const string EdDsa = "EdDSA";
+}