Update README.md

Author: OlegNadymov

README.md

@@ -1,6 +1,6 @@
 # Spoleto.TrueApi
 
-**Spoleto.TrueApi** is an unofficial library to work with True API.
+**Spoleto.TrueApi** is an unofficial library to work with [True API](https://docs.crpt.ru/gismt/True_API/).
 
 
 ## Installation
@@ -26,4 +26,4 @@ var result = await trueApiProvider.GetProcessingResultAsync(settings, "ON_NSCHFD
 
 // or sync version:
 var result = trueApiProvider.GetProcessingResult(settings, "ON_NSCHFDOPPR_file_name");
-```
+```