Clarify the descriptions of test-case-data-related modules

Signed-off-by: Gilles Peskine <[email protected]>

scripts/mbedtls_dev/test_case.py

@@ -1,4 +1,4 @@
-"""Library for generating Mbed TLS test data.
+"""Library for constructing an Mbed TLS test case.
 """
 
 # Copyright The Mbed TLS Contributors

scripts/mbedtls_dev/test_data_generation.py

@@ -1,4 +1,7 @@
-"""Common test generation classes and main function.
+"""Common code for test data generation.
+
+This module defines classes that are of general use to automatically
+generate .data files for unit tests, as well as a main function.
 
 These are used both by generate_psa_tests.py and generate_bignum_tests.py.
 """