code_samples/README: link explore API
code_samples/README: link explore API

artspb/intellij-sdk-docs,JetBrains/intellij-sdk-docs,artspb/intellij-sdk-docs,JetBrains/intellij-sdk-docs,artspb/intellij-sdk-docs,artspb/intellij-sdk-docs,JetBrains/intellij-sdk-docs