Added setup info to error message (relates to #79)

Author: holgerbrandl

README.md

@@ -381,10 +381,9 @@ kscript --idea CountRecords.kts
 ```
 This will open [IntelliJ IDEA](https://www.jetbrains.com/idea/) with a minimalistic project containing just your (1) `<script>` and  (2) a generated `gradle.build` file:
 
-This assumes that you have a command line launcher named `idea`. Add one from Intellij via the `tools -> Create Command-line Launcher` option.
-
 ![](misc/readme_images/minus_idea.png)
 
+This assumes that you have the Intellij IDEA command line launcher `idea` in your `PATH`. It can be created in IntelliJ under `Tools -> Create Command-line Launcher`
 
 FAQ
 ---

src/main/kotlin/kscript/app/AppHelpers.kt

@@ -94,7 +94,7 @@ object ShellUtils {
 
     fun isInPath(tool: String) = evalBash("which $tool").stdout.trim().isNotBlank()
 
-    fun requireInPath(tool: String) = errorIf(!isInPath(tool)) { "$tool is not in PATH" }
+    fun requireInPath(tool: String, msg: String = "$tool is not in PATH") = errorIf(!isInPath(tool)) { msg }
 
 }
 
@@ -193,7 +193,7 @@ fun info(msg: String) = System.err.println(msg)
 
 
 fun launchIdeaWithKscriptlet(scriptFile: File, dependencies: List<String>, customRepos: List<MavenRepo>): String {
-    requireInPath("idea")
+    requireInPath("idea", "Could not find 'idea' in your PATH. It can be created in IntelliJ under `Tools -> Create Command-line Launcher`")
 
     System.err.println("Setting up idea project from ${scriptFile}")