init the pFL-bench scripts

[yxdyc]

init the pFL-bench scripts and README.

[DavdGao]

It looks good to me.
Considering the code is actually running with the other branch, it is suggested to copy all these scripts into the specific branch.

[yxdyc]

It looks good to me. Considering the code is actually running with the other branch, it is suggested to copy all these scripts into the specific branch.

Yes, all these scripts are in the another branch. As the README said You can find the full scripts from the another [branch](https://github.com/alibaba/FederatedScope/tree/Feature/pfl_bench/scripts/personalization_exp_scripts/pfl_bench)

[DavdGao]

I'm not sure, maybe it's better to place the scripts in the same directory for both master and Feature/pfl_bench?

[yxdyc]

I'm not sure, maybe it's better to place the scripts in the same directory for both master and Feature/pfl_bench?

If in master, this PR will involves ~600 files and 5w+ codes. So I put them into a zip file, and refer readers to the file link as README said: You can find the full scripts from the another [branch](https://github.com/alibaba/FederatedScope/tree/Feature/pfl_bench/scripts/personalization_exp_scripts/pfl_bench) or the packed small zip [file](https://federatedscope.oss-cn-beijing.aliyuncs.com/pfl_bench_scripts.zip), in which we organize the scripts for all the methods and all the datasets as multiple directories named by dataset name.

[xieyxclack]

LGTM