Fix data schema resolution dir for subprojects

Author: koperagen

core/src/main/kotlin/org/jetbrains/kotlinx/dataframe/annotations/ImportDataSchema.kt

@@ -9,7 +9,7 @@ package org.jetbrains.kotlinx.dataframe.annotations
  * @param name name of the generated interface
  * @param path URL or relative path to data.
  * if path starts with protocol (http, https, ftp), it's considered a URL. Otherwise, it's treated as relative path.
- * By default, it will be resolved relatively to project root dir, i.e. File(projectRootDir, path)
+ * By default, it will be resolved relatively to project dir, i.e. File(projectDir, path)
  * You can configure it by passing `dataframe.resolutionDir` option to preprocessor, see https://kotlinlang.org/docs/ksp-quickstart.html#pass-options-to-processors
  * @param visibility visibility of the generated interface.
  * @param normalizationDelimiters if not empty, split property names by delimiters,

plugins/dataframe-gradle-plugin/src/main/kotlin/org/jetbrains/dataframe/gradle/ConvenienceSchemaGeneratorPlugin.kt

@@ -23,6 +23,6 @@ internal class KspPluginApplier : Plugin<Project> {
         target.configurations.getByName("ksp").dependencies.add(
             target.dependencies.create("org.jetbrains.kotlinx.dataframe:symbol-processor:$preprocessorVersion")
         )
-        target.extensions.getByType<KspExtension>().arg("dataframe.resolutionDir", target.rootDir.absolutePath)
+        target.extensions.getByType<KspExtension>().arg("dataframe.resolutionDir", target.projectDir.absolutePath)
     }
 }

plugins/symbol-processor/src/main/kotlin/org/jetbrains/dataframe/ksp/DataSchemaGenerator.kt

@@ -101,7 +101,7 @@ class DataSchemaGenerator(
     private fun reportMissingKspArgument(file: KSFile) {
         logger.error("""
         |KSP option with key "dataframe.resolutionDir" must be set in order to use relative path in @${ImportDataSchema::class.simpleName}
-        |DataFrame Gradle plugin should set it by default to "project.rootDir".
+        |DataFrame Gradle plugin should set it by default to "project.projectDir".
         |If you do not use DataFrame Gradle plugin, configure option manually 
     """.trimMargin(), symbol = file)
     }