Update README in analysis-kotlin-symbols (#3578)

The README file for the 'dokka-subprojects/analysis-kotlin-symbols' subproject has been updated. This includes an explanation of the project's entry point, instructions on how to run tests with a custom version of Analysis API, and guidelines on how to build and publish the project locally.

dokka-subprojects/analysis-kotlin-symbols/README.md

@@ -21,4 +21,34 @@ The `.jar` produced by this project shadows all dependencies. There are several
 
 To build it with an override version of Analysis API, the property 
 `org.jetbrains.dokka.build.overrideAnalysisAPIVersion=2.2.0-dev-*` should be added to the project. Any version can be set in the property instead of `2.2.0-dev-*`.
-
+
+### Entry point
+
+The main entry point is `DefaultSymbolToDocumentableTranslator` (this is an extension for [the extension point](https://kotlin.github.io/dokka/1.9.20/developer_guide/architecture/extension_points/core_extensions/#sourcetodocumentabletranslator) ), that is used by the Dokka core to build Documentable model by a source set.
+
+Across running Dokka we keep `StandaloneAnalysisAPISession` and `KtSourceModule` instances from Analysis API into `KotlinAnalysis`.
+`KotlinAnalysis` is used in `DefaultSymbolToDocumentableTranslator` and other services that need an additional analysis.
+
+### How to run the Dokka tests with a custom version of Analysis API?
+
+- To change the version of the Analysis API in Dokka, the property `kotlin-compiler-k2` in `gradle/libs.versions.toml`  should be changed to a needed version.
+  _Note:_ You may need to add a local repository in `settings.gradle.kts`
+  _Note #2:_ You can use the property `org.jetbrains.dokka.build.overrideAnalysisAPIVersion` instead of `gradle/libs.versions.toml`. 
+- The `gradle  :symbolsTest` Gradle task should be used to run Dokka unit tests with the only K2 analysis
+- The `gradle :descriptorsTest` task can be used to check the K1 analysis
+- Dokka also has integration tests. To run them, `:integrationTest` with the property `org.jetbrains.dokka.integration_test.useK2=true`   (or `gradlew integrationTest -Porg.jetbrains.dokka.integration_test.useK2=true`) should be called.
+  They are run on [TeamCity](https://teamcity.jetbrains.com/buildConfiguration/KotlinTools_Dokka_DokkaIntegrationTestsK2?mode=builds#all-projects).
+  _Note:_ Currently, the integration tests do not check generated content very well.  For testing analysis, It is better to run unit tests.
+
+#### How to run the Dokka unit-tests with a custom version of Analysis API on TeamCity?
+
+By default, we run unit tests on TeamCity against the latest Analysis API by a schedule [here](https://teamcity.jetbrains.com/buildConfiguration/KotlinTools_Dokka_ScheduledDokkaTestsK2?mode=builds#all-projects).  It is possible to trigger a run with a custom version of Analysis API (the parameter `Analysis API version` should be used).
+
+
+
+### How to build/publish Dokka locally?
+
+- You can use the `gradle :publishToMavenLocal` task to publish Dokka locally.
+- To build Dokka without running testing, using the `gradle assemble` task is recommended since the tests are time-consuming.
+
+See the detailed guide [here](https://kotlin.github.io/dokka/1.9.20/developer_guide/workflow/).