1655 doc with options obsolete usage of with (#1657)

* Remove internal methods not usable outside the assembly
- The `ConfigOptionsExtensions` is a internal static class

* Replace the method `With` (deprecated) by `WithOptions`

Author: cedric-cf

docs/articles/configs/configoptions.md

@@ -27,15 +27,12 @@ public class Config : ManualConfig
 {
     public Config()
     {
-        Options.Set(true, ConfigOptions.JoinSummary);
-        Options.Set(true, ConfigOptions.DisableLogFile);
-
-        // or
-        Options.Set(true, ConfigOptions.JoinSummary | ConfigOptions.DisableLogFile);
-
-        // or using the With() factory method:
-        this.With(ConfigOptions.JoinSummary)
-            .With(ConfigOptions.DisableLogFile);
+        // Using the WithOptions() factory method:
+        this.WithOptions(ConfigOptions.JoinSummary)
+            .WithOptions(ConfigOptions.DisableLogFile);
+        
+        // Or (The ConfigOptions Enum is defined as a BitField)
+        this.WithOptions(ConfigOptions.JoinSummary | ConfigOptions.DisableLogFile);
 
     }
 }
@@ -50,9 +47,9 @@ public class Config : ManualConfig
             .Run<Benchmarks>(
                 ManualConfig
                     .Create(DefaultConfig.Instance)
-                    .With(ConfigOptions.JoinSummary)
-                    .With(ConfigOptions.DisableLogFile)
+                    .WithOptions(ConfigOptions.JoinSummary)
+                    .WithOptions(ConfigOptions.DisableLogFile)
                     // or
-                    .With(ConfigOptions.JoinSummary | ConfigOptions.DisableLogFile));
+                    .WithOptions(ConfigOptions.JoinSummary | ConfigOptions.DisableLogFile));
     }
 ```