update readme

Author: AndreiKingsley

core/README.md

@@ -10,28 +10,6 @@ At the moment, these integrations are still part of the `:core` module:
 - (deprecated) csv/tsv
 - html
 
-### Korro code samples
-
-Code samples for the documentation website reside
-in [core/.../test/.../samples/api](./src/test/kotlin/org/jetbrains/kotlinx/dataframe/samples/api) (for samples that depend solely on `dataframe-core`),
-and [tests/.../samples/api](../tests/src/test/kotlin/org/jetbrains/kotlinx/dataframe/samples/api) (for samples can depend on other I/O modules)
-and they are copied over to Markdown files in [docs/StardustDocs/topics](../docs/StardustDocs/topics)
-by [Korro](https://github.com/devcrocod/korro).
-
-### ~~Explainer dataframes~~ NOTE: This is being moved to [tests](../tests)
-
-Aside from code samples, `@TransformDataFrameExpressions` annotated test functions also generate sample
-dataframe HTML files that can be used as iFrames on the documentation website.
-They are tested, generated, and copied over to [docs/StardustDocs/resources/snippets](../docs/StardustDocs/resources/snippets) by
-our "explainer" [plugin callback proxy](./src/test/kotlin/org/jetbrains/kotlinx/dataframe/explainer),
-which hooks into [the TestBase class](./src/test/kotlin/org/jetbrains/kotlinx/dataframe/samples/api/TestBase.kt) and
-retrieves the intermediate DataFrame expressions thanks to our "explainer" compiler plugin
-[:plugins:expressions-converter](../plugins/expressions-converter).
-
-We can also generate "normal" DataFrame samples for the website. This can be done using the
-[OtherSamples class](./src/test/kotlin/org/jetbrains/kotlinx/dataframe/samples/api/OtherSamples.kt). Generated
-HTML files will be stored in [docs/StardustDocs/resources/snippets/manual](../docs/StardustDocs/resources/snippets/manual).
-
 ### KoDEx
 
 The code you're working on needs to be edited in [src](src), but the KDocs are processed by

samples/README.md

@@ -1,12 +1,39 @@
-## :tests
-
-Code samples for the documentation website reside in [core/.../test/.../samples/api](../core/src/test/kotlin/org/jetbrains/kotlinx/dataframe/samples/api)
-(for samples that depend solely on `dataframe-core`),
-and [tests/.../samples/api](/src/test/kotlin/org/jetbrains/kotlinx/dataframe/samples/api) (for samples can depend on other I/O modules)
-and they are copied over to Markdown files in [docs/StardustDocs/topics](../docs/StardustDocs/topics)
-by [Korro](https://github.com/devcrocod/korro).
-
-This module might be merged with [:core](../core): [Issue #898](https://github.com/Kotlin/dataframe/issues/898).
- 
-Uses Kandy samples util.
-See https://github.com/Kotlin/kandy/blob/samples_util/util/kandy-samples-utils/README.md for more details.
+## :samples
+
+Code samples as well as DataFrame iframes and Kandy plot images for the 
+[documentation website](https://github.com/Kotlin/dataframe).
+
+### Korro
+
+Saves code samples using [Korro](https://github.com/devcrocod/korro).
+
+To save / update samples:
+* Run `korroClean` and `korro` gradle tasks.
+
+**Important**: may work incorrectly until 
+[migration from `:core` is not finished](https://github.com/Kotlin/dataframe/issues/898).
+Run Korro tasks **for the whole project**.
+
+### SampleHelper
+
+[`SampleHelper`](https://github.com/Kotlin/kandy/blob/samples_util/util/kandy-samples-utils/README.md)
+allows to save resulting Kandy plots as SVG images and `DataFrame`s as iframes.
+
+Running tests in this module will save or update these samples.
+
+**Important**: 
+
+1) if the sample is changed, check if it is (так и надо было или нет короче переформулируй).
+You can track it with the help of the git file changes tracker in IDEA.
+2) All iframes should be added as resources in [this file](../docs/StardustDocs/topics/_shadow_resources.md). 
+Run [this script](https://github.com/Kotlin/kandy/blob/samples_util/util/kandy-samples-utils/README.md#how-to-use)
+to update them.
+
+### Notebook-To-Doc
+
+Kotlin notebook can be easily converted to a documentation using 
+[this script](https://github.com/Kotlin/kandy/blob/samples_util/util/kandy-samples-utils/README.md#how-to-use).
+It produces two files: `.kt` and `.md`. 
+* Place `.kt` file in the tests in this module, and run it.
+* Place `.md` file in the [docs topics directory](../docs/StardustDocs/topics).
+* Run Korro tasks.