image/jpeg: implement jpeg decoding for baseline and extended sequential jpegs

core/image/jpeg/jpeg_os.odin

@@ -0,0 +1,18 @@
+package jpeg
+
+import "core:os"
+
+load :: proc{load_from_file, load_from_bytes, load_from_context}
+
+load_from_file :: proc(filename: string, options := Options{}, allocator := context.allocator) -> (img: ^Image, err: Error) {
+	context.allocator = allocator
+
+	data, ok := os.read_entire_file(filename)
+	defer delete(data)
+
+	if ok {
+		return load_from_bytes(data, options)
+	} else {
+		return nil, .Unable_To_Read_File
+	}
+}