docs: Documented error codes

app/src/incphub/include/incphub/incphub.h

@@ -6,12 +6,19 @@
 #include "ntl/ntl.h"
 #include "nil/nil.h"
 
+/// @brief Success
 #define INCPHUB_OK (0)
+/// @brief Unspecified error
 #define INCPHUB_ERR (1)
+/// @brief Invalid argument
 #define INCPHUB_EINVAL (2)
+/// @brief Resource or entry not found
 #define INCPHUB_ENOTFOUND (3)
+/// @brief Resource in use
 #define INCPHUB_EBUSY (4)
+/// @brief Resource temporarily unavailable
 #define INCPHUB_EAGAIN (5)
+/// @brief Could not allocate memory
 #define INCPHUB_ENOMEM (6)
 
 typedef struct {