Add initial database context and first entity

Component/Entry/Repository/EntryConfiguration.cs

@@ -0,0 +1,13 @@
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Metadata.Builders;
+
+namespace Diary.Component.Entry.Repository
+{
+	public class EntryConfiguration : IEntityTypeConfiguration<Entry>
+	{
+		public void Configure(EntityTypeBuilder<Entry> builder)
+		{
+			
+		}
+	}
+}