TRACK_HINTS.md in trackler-2.1.0.12

- old
+ new

@@ -3,6 +3,6 @@
 
 ## How to implement your solution
 In each problem folder, there is a file named `<exercise_name>.R` containing a function that returns a `NULL` value. Place your implementation inside the body of the function.
 
 ## How to run tests
-Inside of RStudio, simply execute the `test_<exercise_name>.R` script. On the command-line, you can also run `Rscript test_<exercise_name>.R`.
+Inside of RStudio, simply execute the `test_<exercise_name>.R` script. This can be conveniently done with [testthat's `auto_test` function](https://www.rdocumentation.org/packages/testthat/topics/auto_test). Because exercism code and tests are in the same folder, use this same path for both  `code_path` and `test_path` parameters. On the command-line, you can also run `Rscript test_<exercise_name>.R`.