Add support for writing fiin files

src/fiin.rs

@@ -4,7 +4,7 @@
 use std::fs::read;
 use std::io::Cursor;
 
-use binrw::BinRead;
+use binrw::{BinRead, BinWrite};
 use binrw::binrw;
 
 use crate::gamedata::MemoryBuffer;
@@ -52,6 +52,17 @@ impl FileInfo {
         FileInfo::read(&mut cursor).ok()
     }
 
+    pub fn write_to_buffer(&self) -> Option<MemoryBuffer> {
+        let mut buffer = MemoryBuffer::new();
+
+        {
+            let mut cursor = Cursor::new(&mut buffer);
+            self.write(&mut cursor).ok()?;
+        }
+
+        Some(buffer)
+    }
+
     /// Creates a new FileInfo structure from a list of filenames. These filenames must be present in
     /// the current working directory in order to be read properly, since it also generates SHA1
     /// hashes.