Cleanup mention of outdated Gradle & example project

Author: koperagen

docs/StardustDocs/topics/concepts/concepts.md

@@ -40,7 +40,6 @@ This is why it was designed to be hierarchical and allows nesting of columns and
 * **Immutable** — every operation returns a new instance of [`DataFrame`](DataFrame.md)  reusing underlying storage wherever it's possible.
 * **Readable** — data transformation operations are defined in DSL close to natural language.
 * **Practical** — provides simple solutions for common problems and the ability to perform complex tasks.
-* **Minimalistic** — simple, yet powerful data model of three [column kinds](DataColumn.md#column-kinds).
 * [**Interoperable**](collectionsInterop.md) — convertable with Kotlin data classes and collections.
   This also means conversion to/from other libraries' data structures is usually quite straightforward!
   See our [examples](https://github.com/Kotlin/dataframe/tree/master/examples/projects) 
@@ -52,9 +51,8 @@ This is why it was designed to be hierarchical and allows nesting of columns and
 * **Typesafe** — the Kotlin DataFrame library provides a mechanism of on-the-fly [**generation of extension properties**](extensionPropertiesApi.md) 
 that correspond to the columns of a dataframe. 
 In interactive notebooks like Jupyter or Datalore, the generation runs after each cell execution. 
-In IntelliJ IDEA there's a Gradle plugin for generation properties based on CSV file or JSON file. 
-Also, we’re working on a compiler plugin that infers and transforms [`DataFrame`](DataFrame.md) schema while typing.
-You can now clone this [project with many examples](https://github.com/koperagen/df-plugin-demo) showcasing how it allows you to reliably use our most convenient extension properties API.
+In IntelliJ IDEA we’re featuring a compiler plugin that infers and transforms [`DataFrame`](DataFrame.md) schema while typing.
+You can now check out this [typical data wrangling pipeline](https://github.com/Kotlin/dataframe/blob/master/examples/projects/kotlin-dataframe-plugin-gradle-example/src/main/kotlin/org/jetbrains/kotlinx/dataframe/examples/plugin/Main.kt) showcasing how it allows you to reliably use our most convenient extension properties API.
 The generated properties ensure you’ll never misspell column name and don’t mess up with its type, and of course nullability is also preserved.
 * [**Polymorphic**](schemas.md) —
   if all columns of a [`DataFrame`](DataFrame.md) instance are presented in another dataframe,