Welcoming OSDN Projects to SourceForge

This is a response to OSDN has been acquired by OSChina.[0,1]

[0] https://www.oschina.net/news/250642/oschina-acquired-osdn

[1] https://jw.ijiwei.com/n/867412

[2] https://technode.com/2023/07/28/former-alibaba-vp-joins-open...