Document generateCompileCommands task better (wpilibsuite#2582)

Includes a warning about not being recommended for most users and mentions clangd

Author: spacey-sooty

source/docs/software/advanced-gradlerio/gradlew-tasks.rst

@@ -10,7 +10,10 @@ This article aims to highlight the gradle commands supported by the WPILib team
 
 ## CompileCommands tasks
 
-``./gradlew generateCompileCommands`` - Generate compile_commands.json for C++ programs. This is a configuration file that is supported by many Integrated Development Environments and build tools.
+``./gradlew generateCompileCommands`` - Generate compile_commands.json for C++ programs. This is a configuration file that is used by clangd, which is supported by many Integrated Development Environments and build tools. This file will be saved in ``build/TargetedCompileCommands/targetplatformandbuildtype`` but needs to be moved to the root of your project. Many IDE's will have a way to specify where this file is found, which you can use instead if you desire. Make sure you have gitignored this file.
+
+.. warning::
+    Using compile commands isn't recommended for most users and has a variety of pitfalls compared to the built-in intellisense.
 
 ## DeployUtils tasks