docs: add Kangwhi-Kim and two contributors

[allcontributors[bot]]

Add @Kangwhi-Kim as a contributor for code.

This was requested by kyunghwan-onepredict in this comment

[kyunghwan-onepredict]

@all-contributors please add @Kangwhi-Kim code

[allcontributors[bot]]

@kyunghwan-onepredict

@Kangwhi-Kim already contributed before to code

[kyunghwan-onepredict]

@all-contributors please remove @Kangwhi-Kim code

[allcontributors[bot]]

@kyunghwan-onepredict

I could not determine your intention.

Basic usage: @all-contributors please add @someone for code, doc and infra

For other usages see the documentation

[kyunghwan-onepredict]

@all-contributors please add @DaeyeopN code

[allcontributors[bot]]

@kyunghwan-onepredict

I've put up a pull request to add @DaeyeopN! :tada:

[kyunghwan-onepredict]

@all-contributors please add @isingmodel review

[allcontributors[bot]]

@kyunghwan-onepredict

I've put up a pull request to add @isingmodel! :tada: