Update CONTRIBUTORS.md

CONTRIBUTORS.md

@@ -410,6 +410,12 @@ We will be listing contributors in alphabetical order, by week, by challenge. At
 
 ---
 
+#### WEEK FOUR - CHALLENGE 17
+---
+
+#### WEEK FOUR - CHALLENGE 18
+---
+
 #### WEEK THREE - CHALLENGE 19
 - [Stuart Leaver](https://github.com/stuartleaver/25-days-of-serverless/tree/master/19-durable-entities) - `python, logic apps`
 - [Barbara Forbes](https://github.com/Ba4bes/25daysofserverless/tree/master/Daya19Balloons) - `Powershell, `
@@ -441,3 +447,19 @@ We will be listing contributors in alphabetical order, by week, by challenge. At
 - [Paweł Haracz](https://github.com/PawelHaracz/25daysofserverless/tree/master/Day23) - `Azure Functions, C#`
 - [Stuart Leaver](https://github.com/stuartleaver/25-days-of-serverless/tree/master/23-instrumenting-functions) - `Azure Functions with C#, Durable Entities, Application Insights, ARM templates`
 - [Marcus Turewicz](https://github.com/marcusturewicz/25-days-of-serverless-challenge/tree/master/Day-23) - `Azure Functions with Node, Application Insights`
+
+
+---
+
+#### WEEK FOUR - CHALLENGE 24
+
+---
+
+#### WEEK FOUR - CHALLENGE 25
+
+- [Barbara 4bes](https://github.com/Ba4bes/25daysofserverless/tree/master/Daya25KheerRecipe) - `PowerShell function App, Cognitive services (SpeechToText), Storage Account`
+- [Paweł Haracz](https://github.com/PawelHaracz/25daysofserverless/tree/master/Day25) - `Twillo, Blob storage, cognitive speech service, dotnet`
+- [Stuart Leaver](https://github.com/stuartleaver/25-days-of-serverless/tree/master/25-audio-transcription) - `C#, Azure Function, Speech to Text Cognitive Service and Twilio`
+- [Marcus Turewicz](https://github.com/marcusturewicz/25-days-of-serverless-challenge/tree/master/Day-25) - `C# Azure Function, Speech to Text and Blob Storage`
+
+---