Merge pull request #1239 from Kotlin/docs_images

add pictures for guides

Author: AndreiKingsley

docs/StardustDocs/images/guides/geoguide_preview.png

@@ -19,50 +19,58 @@ A curated list of Kotlin DataFrame guides and examples that walk you through com
 
 Explore our structured, in-depth guides to steadily improve your Kotlin DataFrame skills — step by step.
 
-* [](quickstart.md) — get started with Kotlin DataFrame in a few simple steps: 
-load data, transform it, and visualize it.
+* [](quickstart.md) — get started with Kotlin DataFrame in a few simple steps:
+  load data, transform it, and visualize it.
+
+<img src="quickstart_preview.png" border-effect="rounded" width="705"/>
+
 * [Enhanced Column Selection DSL](https://blog.jetbrains.com/kotlin/2024/07/enhanced-column-selection-dsl-in-kotlin-dataframe/)
- — explore powerful DSL for typesafe and flexible column selection in Kotlin DataFrame.
+  — explore powerful DSL for typesafe and flexible column selection in Kotlin DataFrame.
 * [](Kotlin-DataFrame-Features-in-Kotlin-Notebook.md)
-  — discover interactive Kotlin DataFrame outputs in 
-[Kotlin Notebook](https://kotlinlang.org/docs/kotlin-notebook-overview.html).
+  — discover interactive Kotlin DataFrame outputs in
+  [Kotlin Notebook](https://kotlinlang.org/docs/kotlin-notebook-overview.html).
+
+<img src="ktnb_features_preview.png" border-effect="rounded" width="705"/>
+
 * [40 Puzzles](https://github.com/Kotlin/dataframe/blob/master/examples/notebooks/puzzles/40%20puzzles.ipynb)
- — inspired by [100 pandas puzzles](https://github.com/ajcr/100-pandas-puzzles).
+  — inspired by [100 pandas puzzles](https://github.com/ajcr/100-pandas-puzzles).
   An interactive guide that takes you from simple tasks to complex challenges,
-teaching you how to solve them using Kotlin DataFrame in a concise and elegant style.
+  teaching you how to solve them using Kotlin DataFrame in a concise and elegant style.
 * [Reading from files: CSV, JSON, ApacheArrow](read.md)
   — read your data from various formats into `DataFrame`.
 * [SQL Databases Interaction](readSqlDatabases.md)
- — set up SQL database access and read query results efficiently into `DataFrame`.
+  — set up SQL database access and read query results efficiently into `DataFrame`.
 * [Custom SQL Database Support](readSqlFromCustomDatabase.md)
   — extend DataFrame library for custom SQL database support.
 * [GeoDataFrame Guide](https://kotlin.github.io/kandy/geo-plotting-guide.html)
-  — explore the GeoDataFrame module that brings a convenient Kotlin DataFrame API to geospatial workflows, 
-enhanced with beautiful Kandy-Geo visualizations (*experimental*).
-* [OpenAPI Guide](https://github.com/Kotlin/dataframe/blob/master/examples/notebooks/json/KeyValueAndOpenApi.ipynb)
- — learn how to parse and explore [OpenAPI](https://swagger.io) JSON structures using Kotlin DataFrame, 
-enabling structured access and intuitive analysis of complex API schemas (*experimental*, supports OpenAPI 3.0.0).
+  — explore the GeoDataFrame module that brings a convenient Kotlin DataFrame API to geospatial workflows,
+  enhanced with beautiful Kandy-Geo visualizations (*experimental*).
 
+<img src="geoguide_preview.png" border-effect="rounded" width="705"/>
+
+* [OpenAPI Guide](https://github.com/Kotlin/dataframe/blob/master/examples/notebooks/json/KeyValueAndOpenApi.ipynb)
+  — learn how to parse and explore [OpenAPI](https://swagger.io) JSON structures using Kotlin DataFrame,
+  enabling structured access and intuitive analysis of complex API schemas (*experimental*, supports OpenAPI 3.0.0).
 
 ## Examples
 
 Explore our extensive collection of practical examples and real-world analytics workflows.
 
-* [Titanic Example](https://github.com/Kotlin/dataframe/blob/master/examples/notebooks/titanic/Titanic.ipynb) 
- — discover the famous "Titanic"
- dataset with the Kotlin DataFrame analysis toolkit 
- and [Kandy](https://kotlin.github.io/kandy/) visualizations.
+* [Titanic Example](https://github.com/Kotlin/dataframe/blob/master/examples/notebooks/titanic/Titanic.ipynb)
+  — discover the famous "Titanic"
+  dataset with the Kotlin DataFrame analysis toolkit
+  and [Kandy](https://kotlin.github.io/kandy/) visualizations.
 
 * [Track and Analyze GitHub Star Growth](https://blog.jetbrains.com/kotlin/2024/08/track-and-analyze-github-star-growth-with-kandy-and-kotlin-dataframe/)
   — query GitHub’s API with the Kotlin Notebook Ktor client,
-  then analyze and visualize the data using Kotlin DataFrame and [Kandy](https://kotlin.github.io/kandy/). 
+  then analyze and visualize the data using Kotlin DataFrame and [Kandy](https://kotlin.github.io/kandy/).
 
-* [GitHub Example](https://github.com/Kotlin/dataframe/blob/master/examples/notebooks/github/github.ipynb) 
- — a practical example of working with deeply nested, hierarchical DataFrames using GitHub data.
+* [GitHub Example](https://github.com/Kotlin/dataframe/blob/master/examples/notebooks/github/github.ipynb)
+  — a practical example of working with deeply nested, hierarchical DataFrames using GitHub data.
 
 * [Netflix Example](https://github.com/Kotlin/dataframe/blob/master/examples/notebooks/netflix/netflix.ipynb)
   — explore TV shows and movies from Netflix with the powerful Kotlin Dataframe API and beautiful
- [Kandy](https://kotlin.github.io/kandy/) visualizations.
+  [Kandy](https://kotlin.github.io/kandy/) visualizations.
 
 * [Top-12 German Companies Financial Analyze](https://github.com/Kotlin/dataframe/blob/master/examples/notebooks/top_12_german_companies)
   — analyze key financial metrics for several major German companies.
@@ -71,13 +79,14 @@ Explore our extensive collection of practical examples and real-world analytics
   — basic Kotlin DataFrame operations on data from [movielens](https://movielens.org/).
 
 * [YouTube Example](https://github.com/Kotlin/dataframe/blob/master/examples/notebooks/youtube/Youtube.ipynb)
-    — explore YouTube videos with YouTube REST API and Kotlin Dataframe.
+  — explore YouTube videos with YouTube REST API and Kotlin Dataframe.
 
-* [IMDb SQL Database Example](https://github.com/zaleslaw/KotlinDataFrame-SQL-Examples/blob/master/notebooks/imdb.ipynb) 
- — analyze IMDb data stored in MariaDB using Kotlin DataFrame 
-and visualize with [Kandy](https://kotlin.github.io/kandy/).
+* [IMDb SQL Database Example](https://github.com/zaleslaw/KotlinDataFrame-SQL-Examples/blob/master/notebooks/imdb.ipynb)
+  — analyze IMDb data stored in MariaDB using Kotlin DataFrame
+  and visualize with [Kandy](https://kotlin.github.io/kandy/).
 
-
-See also [Kandy User Guides](https://kotlin.github.io/kandy/user-guide.html) 
+See also [Kandy User Guides](https://kotlin.github.io/kandy/user-guide.html)
 and [Examples Gallery](https://kotlin.github.io/kandy/examples.html)
 for the best data visualizations using Kotlin DataFrame and Kandy together!
+
+<img src="kandy_gallery_preview.png" border-effect="rounded" width="705"/>