Relicensing to GPLv2

I'm working on replacing the iSH syscall handling code with a port of the actual Linux kernel, which requires relicensing iSH as GPLv2 so it can be linked with the Linux kernel which is also GPLv2. (Turns out GPLv2 is not compatible with GPLv3.) In order to do this, I need to get permission from all of you (since I didn't make you sign a CLA).

If you're mentioned below, you've made a contribution and haven't given permission to relicense your contribution in the [LICENSE.md](https://github.com/ish-app/ish/edit/master/LICENSE.md) file. Please do so! The best way is to [make a pull request adding your name and email](https://github.com/ish-app/ish/edit/master/LICENSE.md).

Thanks for your contribution!

@0b101 @AngeloHYang @BastianInuk @CRKatri @ChaosTong @NoahPeeters @SEProblem @alexismarquis @asdfugil @cmelbye @elchris414 @josete89 @kkk669 @krystophny @lightlace @lorenzodla @lunixbochs @MatthewMerrill @mnpn03 @sdushantha @stek29 @thunderkeys @wishstudio @woachk @zhuoweiz

Review LICENSE.md and confirm that your contribution is listed among the people asked for permission. If so, add your name and email through a pull request as requested; no test files or test commands are mentioned.

Written by the indexing model from the issue text.