fix docs

Author: koperagen

docs/StardustDocs/topics/gradle.md

@@ -124,7 +124,7 @@ get enums, correct inheritance and overall better type safety.
 
 First of all, you will need the extra dependency:
 
-```kts
+```kotlin
 implementation("org.jetbrains.kotlinx:dataframe-openapi:$dataframe_version")
 ```
 

docs/StardustDocs/topics/schemas.md

@@ -242,13 +242,13 @@ do this in Jupyter notebooks. There is only a slight difference in notation:
 
 Import the schema using any path (`String`), `URL`, or `File`:
 
-```kts
+```kotlin
 val PetStore = importDataSchema("https://petstore3.swagger.io/api/v3/openapi.json")
 ```
 
 and then from next cell you run and onwards, you can call, for example:
 
-```kts
+```kotlin
 val df = PetStore.Pet.readJson("https://petstore3.swagger.io/api/v3/pet/findByStatus?status=available")
 ```