Update readme with the correct directory name for tests cases

Signed-off-by: Luis Araujo <luis.araujo@collabora.co.uk>

README.md

@@ -35,12 +35,12 @@ That will create a `<test-case-name>.html` page.
 
 To render a complete set of test cases inside a directory, just pass a directory
 instead of a file to the command, and optionally pass a new directory path with
-`-d` flag so all the newly generated test cases are saved there instead of the
+the `-d` flag so all the newly generated test cases are saved there instead of the
 current directory:
 
 ```
-$ ./render-test-case ../test-cases -d apertis-tests-cases-v0.1/
+$ ./render-test-case ../tests-cases/ -d apertis-tests-cases-v0.1/
 ```
 
-Now all the tests cases should be available inside the `apertis-tests-cases-v0.1/`
-directory.
+Now all the html tests cases should be available inside the
+`apertis-tests-cases-v0.1/` directory.