Sync SDL3 header -> wiki

SDL3/SDL_WriteStorageFile.md

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+###### (This is the documentation for SDL3, which is under heavy development and the API is changing! [SDL2](https://wiki.libsdl.org/SDL2/) is the current stable version!)
+# SDL_WriteStorageFile
+
+Synchronously write a file from client memory into a storage container.
+
+## Header File
+
+Defined in [SDL_storage.h](https://github.com/libsdl-org/SDL/blob/main/include/SDL3/SDL_storage.h), but apps should use `#include <SDL3/SDL.h>`
+
+## Syntax
+
+```c
+int SDL_WriteStorageFile(SDL_Storage *storage, const char *path, const void *source, Uint64 length);
+
+```
+
+## Function Parameters
+
+| | |
+| --------------- | -------------------------------------- |
+| **storage** | a storage container to write to |
+| **path** | the relative path of the file to write |
+| **source** | a client-provided buffer to write from |
+| **length** | the length of the source buffer |
+
+## Return Value
+
+Returns 0 if the file was written, a negative value otherwise; call
+[SDL_GetError](SDL_GetError)() for more information.
+
+## Version
+
+This function is available since SDL 3.0.0.
+
+## See Also
+
+* [SDL_GetStorageSpaceRemaining](SDL_GetStorageSpaceRemaining)
+* [SDL_ReadStorageFile](SDL_ReadStorageFile)
+* [SDL_StorageReady](SDL_StorageReady)
+
+----
+[CategoryAPI](CategoryAPI), [CategoryAPIFunction](CategoryAPIFunction)
+