Guides for Serilog and EFCore (#2134)

* Add serilog guide

* added suggestions from Rozen

* Add efcore guide

* Fix review changes

* Fix grammatical errors & review points

docs/guides/other_libs/samples/DbContextSample.cs

@@ -0,0 +1,19 @@
+// ApplicationDbContext.cs
+using Microsoft.EntityFrameworkCore;
+
+public class ApplicationDbContext : DbContext
+{
+    public ApplicationDbContext(DbContextOptions<ApplicationDbContext> options) : base(options)
+    {
+
+    }
+
+    public DbSet<UserEntity> Users { get; set; } = null!;
+}
+
+// UserEntity.cs
+public class UserEntity
+{
+    public ulong Id { get; set; }
+    public string Name { get; set; }
+}