Updating the save mechanism by creating an intermediary SaveData struct (#472)

* Make save changes their own branch

* Make SaveData tags char[] instead of u32[]

* Make Game and Options data saving independent

* removed unused functions

* Potential fix for pull request finding

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

* mark save sections as valid only after they are actually written to SRAM

* fix comparison between different integer types

* Implement some suggestions from @ricfehr3

* Add extensive documentation on the structure of the savefile

* fix doxygen doc generation

* fix it again

---------

Co-authored-by: MathisMartin31 <mathis.martin31@gmail.com>
Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

include/save.h

@@ -2,6 +2,27 @@
  * @file save.h
  *
  * @brief Utils functions to save/load data structures from/to the SRAM.
+ *
+ * Here is an overwiew of the contents of a valid save file.
+ *
+ * ```
+ * ┌─────────────┐ <-- SaveHeader
+ * │   Header    │
+ * ├─────────────┤ <-- SaveOptions
+ * │   Options   │
+ * ├─────────────┤ <-- SaveGame
+ * │ Engine vars │
+ * │   Jokers    │
+ * └─────────────┘
+ * ```
+ *
+ * SaveHeader indicates save validity by its presence.
+ * SaveOptions contains options values set in the corresponding menu and apply to the game itself.
+ * SaveGame contains values tied to a run with round, ante, money, owned Jokers etc...
+ *
+ * @sa SaveHeader, SaveOptions, SaveGame
+ *
+ * I strongly recommend using `xxd -l 512 -e -g 4 <gbalatro.sav>` to view the contents of the save
  */
 #ifndef SAVE_H
 #define SAVE_H
@@ -11,15 +32,27 @@
 #include <tonc.h>
 
 /**
- * @brief Save game data to SRAM.
+ * @brief Save current run data to SRAM.
  */
-void save_game();
+void save_game(void);
 
 /**
- * @brief Load game data from SRAM.
+ * @brief Load previous run data from SRAM.
  *
  * @sa save_game
  */
-void load_game();
+void load_game(void);
+
+/**
+ * @brief Save options values to SRAM.
+ */
+void save_options(void);
+
+/**
+ * @brief Load options values from SRAM.
+ *
+ * @sa save_options
+ */
+void load_options(void);
 
 #endif // SAVE_H