Merge pull request #16 from tsimbalar/doc-minimul-level-overrides

Add doc for serilog:minimum-level:override: [Skip CI]

Author: nblumhardt

README.md

@@ -104,4 +104,25 @@ For example, to add the property `Release` with the value `"1.2-develop"` to all
     <add key="serilog:enrich:with-property:Release" value="1.2-develop" />
 ```
 
+### Adding minimum level overrides
+
+Since Serilog 2.1, [minimum level overrides](https://nblumhardt.com/2016/07/serilog-2-minimumlevel-override/) can be added to change the minimum level for some specific namespaces. This is done with the setting key `serilog:minimum-level:override:` followed by the *source context prefix*.
+
+For instance, the following are equivalent :
+
+```csharp
+Log.Logger = new LoggerConfiguration()
+    .MinimumLevel.Information()
+    .MinimumLevel.Override("Microsoft", LogEventLevel.Warning)
+    .MinimumLevel.Override("Microsoft.AspNetCore.Mvc", LogEventLevel.Error)
+```
+
+and in XML
+
+```xml
+    <add key="serilog:minimum-level" value="Information" />
+    <add key="serilog:minimum-level:override:Microsoft" value="Warning" />
+    <add key="serilog:minimum-level:override:Microsoft.AspNetCore.Mvc" value="Error" />
+```
+
 See the [Serilog documentation](https://github.com/serilog/serilog/wiki/AppSettings) for further information.