Format and document utility files (#246)

* Format and document utility files

* Add Doxyfile

* small updates for cleanup

* Final touches for util docs

* Replace `_` with `s_` for static functions

* update for clang-format changes

* Update include/audio_utils.h

Co-authored-by: MeirGavish <meir.gavish@gmail.com>

* Apply suggestions from code review

Co-authored-by: MeirGavish <meir.gavish@gmail.com>

* Update include/audio_utils.h

Co-authored-by: MeirGavish <meir.gavish@gmail.com>

* Update include/graphic_utils.h

Co-authored-by: MeirGavish <meir.gavish@gmail.com>

* Make clang-format happy :)

* Update gitignore for doxygen

* restor graphic_utils.c to main

* update graphics utils

* tmp

* tmp

* get it to compile

* fix some bad merge mistakes

* Fix clang format

* Apply suggestions from code review

Co-authored-by: MeirGavish <meir.gavish@gmail.com>

* make clang-format happy

---------

Co-authored-by: MeirGavish <meir.gavish@gmail.com>

include/list.h

@@ -1,9 +1,10 @@
-/** @file list.h
+/**
+ * @file list.h
  *
- *  @brief A doubly-linked list
+ * @brief A doubly-linked list
  *
- *  List Implementation
- *  ===================
+ * List Implementation
+ * ===================
  *
  *  - This @ref List operates as a linked list @ref ListNodes. It operates as a regular
  * doubly-linked list but doesn't allocate memory and rather gets @ref ListNodes from a pool.
@@ -13,6 +14,13 @@
 
 #include <stdbool.h>
 
+/**
+ * @def MAX_LIST_NODES
+ * @brief Number of reserved list nodes.
+ *
+ * Number of list nodes available from the pool of @ref ListNode . This should
+ * be set to to the maximum number of list nodes needed at once.
+ */
 #define MAX_LIST_NODES 128
 
 typedef struct ListNode ListNode;