doc(README): restructure test definition steps

Author: rouson

README.md

@@ -6,12 +6,16 @@ via Julienne's `string_t` derived type.  The target strings include command-line
 via Julienne's `command_line_t` type  and format strings generated by functions in Julienne's `formats_m` module.
 
 Users construct tests by
-* Extending Julienne's `test_t` abstract derived type,
-* Constructing an array of `test_description_t` objects, each of which encapsulates
-   * A string describing what functionality is being tested and
-   * The name of a function that performs a test and produces one or more `test_diagnosis_t` result objects, each of which encapsulates
-      * A `logical` indicator of the test outcome (`.true.` denotes a pass) and
-      * A `character` or `string_t` diagnostics string.
+1. Extending Julienne's `test_t` abstract derived type,
+2. Defining a `subject()` function that returns a description of the entity being tested,
+3. Defining a `results()` function that
+    - Constructs an array of `test_description_t` objects, each of which encapsulates
+        * A string describing a function that produces one or more `test_diagnosis_t` result objects, each of which encapsulates
+            * A `logical` indicator of whether the test passed and
+            * A `character` or `string_t` diagnostics string.
+        * The corresponding function name and
+    - Produces an array of `test_result_t` objects.
+
 
 Julienne empowers users to customize the diagnostic information that prints when tests fail.
 For this purpose, Julienne's `string_t` constructors convert various data types, kinds, and ranks to character data.