AIO commit

Sorry for the late commit, forgot to commit and push it on Saturday 7th.
Thank god there are moodle reminders

AdventOfCode/AdventOfCode.Test/Day1Test.cs

@@ -0,0 +1,22 @@
+namespace AdventOfCode.Test;
+
+public sealed class Day1Test
+{
+    private string _input = "3   4\n4   3\n2   5\n1   3\n3   9\n3   3";
+    
+    [Fact]
+    public void Part1()
+    {
+        var day1 = new Day1();
+        var result = day1.Part1(_input);
+        Assert.Equal(11, result);
+    }
+    
+    [Fact]
+    public void Part2()
+    {
+        var day1 = new Day1();
+        var result = day1.Part2(_input);
+        Assert.Equal(31, result);
+    }
+}