Add version endpoint

Features/Version/Get/GetVersionEndpoint.cs

@@ -0,0 +1,40 @@
+
+using System.Text;
+
+namespace ConnectionsAPI.Features.Version.Get
+{
+    public class GetVersionEndpoint : EndpointWithoutRequest<string>
+    {
+        private static readonly int START_YEAR = 2024;
+
+        public override void Configure()
+        {
+            Get("/version");
+            AllowAnonymous();
+        }
+
+        public override async Task HandleAsync(CancellationToken ct)
+        {
+            StringBuilder responseBuilder = new();
+
+            responseBuilder.Append("ConnectionsAPI ©");
+            if (DateTime.UtcNow.Year != START_YEAR)
+            {
+                responseBuilder.AppendFormat("{0} - {1}; ", START_YEAR, DateTime.UtcNow.Year);
+            }
+            else
+            {
+                responseBuilder.AppendFormat("{0}; ", DateTime.UtcNow.Year);
+            }
+
+            responseBuilder.Append("by Mate Farkas; ");
+
+            responseBuilder.AppendFormat("v{0}-{1}+{2};",
+                                         GitVersionInformation.MajorMinorPatch,
+                                         GitVersionInformation.ShortSha,
+                                         GitVersionInformation.EscapedBranchName);
+
+            await SendStringAsync(responseBuilder.ToString(), cancellation: ct);
+        }
+    }
+}