docs: Update documentation generation with missing entries

This adds missing entries for documentation generation, both for tests
and the API reference.

The list of tests is made complete and ordered alphabetically, with
modified descriptions for consistency.

More files are added to the API reference, with a minimalistic
description block added to them when it was missing.

Signed-off-by: Paul Kocialkowski <paul.kocialkowski@linux.intel.com>
Reviewed-by: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
diff --git a/lib/igt_rand.c b/lib/igt_rand.c
index b8d3a92..664a476 100644
--- a/lib/igt_rand.c
+++ b/lib/igt_rand.c
@@ -1,5 +1,12 @@
 #include "igt_rand.h"
 
+/**
+ * SECTION:igt_rand
+ * @short_description: Random numbers helper library
+ * @title: Random
+ * @include: igt_rand.h
+ */
+
 static uint32_t global = 0x12345678;
 
 uint32_t hars_petruska_f54_1_random_seed(uint32_t new_state)