Add internal provider

Co-authored-by: Julien Salleyron <julien.salleyron@gmail.com>

docs/content/operations/ping.md

@@ -58,3 +58,23 @@ ping:
 --entryPoints.ping.address=":8082"
 --ping.entryPoint="ping"
 ```
+
+#### `manualRouting`
+
+_Optional, Default=false_
+
+If `manualRouting` is `true`, it disables the default internal router in order to allow one to create a custom router for the `ping@internal` service.
+
+```toml tab="File (TOML)"
+[ping]
+  manualRouting = true
+```
+
+```yaml tab="File (YAML)"
+ping:
+  manualRouting: true
+```
+
+```bash tab="CLI"
+--ping.manualrouting=true
+```