Fix audit findings for coverage, architecture checks, and XML docs

tests/CBDD.Tests/SchemaTests.cs

@@ -16,6 +16,9 @@ public class SchemaTests
         foreach (var k in new[] { "_id", "name", "mainaddress", "otheraddresses", "tags", "secret", "street", "city" }) _testKeyMap[k] = id++;
     }
 
+    /// <summary>
+    /// Executes UsedKeys_ShouldReturnAllKeys.
+    /// </summary>
     [Fact]
     public void UsedKeys_ShouldReturnAllKeys()
     {
@@ -33,6 +36,9 @@ public class SchemaTests
 
     }
 
+    /// <summary>
+    /// Executes GetSchema_ShouldReturnBsonSchema.
+    /// </summary>
     [Fact]
     public void GetSchema_ShouldReturnBsonSchema()
     {