Increase PKG_VERSION to 0.2.1, created release files

The release files (tar.gz+zip) are created with `make release`
and uploaded to the new release in github:

https://github.com/UB-Mannheim/ocr-fileformat/releases/tag/v0.2.1

Author: zuphilip

Makefile

@@ -1,5 +1,5 @@
 PKG_NAME = ocr-fileformat
-PKG_VERSION = 0.2.0
+PKG_VERSION = 0.2.1
 DOCKER_IMAGE = ubma/ocr-fileformat
 
 CP = cp -r