【PPMix No.3】support qwen2-vl-2b lora finetune

[sunnychenxiwang]

support qwen2-vl lora finetue
1.update file 'paddlemix/examples/qwen2_vl/qwen2vl_finetune.py' to support lora finetune
2.add new file 'paddlemix/examples/qwen2_vl/shell/basline_2b_lora_bs32_1e8.sh'
3.update file 'paddlemix/examples/qwen2_vl/README.md'

[paddle-bot]

Thanks for your contribution!

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you all sign our Contributor License Agreement before we can accept your contribution.
2 out of 3 committers have signed the CLA.

✅ nemonameless
✅ sunnychenxiwang
❌ wcx881212
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[luyao-cv]

readme里面放下这个截图。截图放paddlemix/demo_images

[sunnychenxiwang]

add lora ft image in readme

[luotao1]

hi, @sunnychenxiwang

• 非常感谢你对飞桨的贡献，我们正在运营一个PFCC组织，会通过定期分享技术知识与发布开发者主导任务的形式持续为飞桨做贡献，详情可见 https://github.com/luotao1 主页说明。
• 如果你对PFCC有兴趣，请发送邮件至 ext_paddle_oss@baidu.com，我们会邀请你加入~