Release Cyd as open source

[micahflee]

There are things that need to be done for this to be possible:

• The GitHub issues are full of feedback from users, including the individual users email addresses. Can we somehow purge old GitHub issues to protect this data?
• Running Cyd requires a server, and you can set it to local, dev, or prod. Should we have all outside contributors use the dev server, and add their emails to the allowlist? Or should we add another mode, free (so we can do npm run config-free to enable free mode) where all premium features just work with no login required? This way people can use this mode while under development... though it would make it trivial for people to then fork and release a totally free version. Something to discuss.
• Pick out a license, probably GPLv3.
• Configure GitHub to include a contributor agreement. I'm not sure the details but maybe we'll need to require all contributors to agree to dual-license their work, both GPL and also giving Lockdown Systems an additional license to use it however we want?
• Add a security vulnerability disclosure policy, in case anyone finds vulnerabilities in our repo and wants to report it. I personally like the idea of having a https://cyd.social/security.txt
• Write a blog post/newsletter to coincide with it making the repo public

[redshiftzero]

For the first item, we can do this: https://docs.github.com/en/communities/moderating-comments-and-conversations/tracking-changes-in-a-comment#deleting-sensitive-information-from-a-comments-history (could do manually since it's <200 issues and only a subset will have sensitive data). I tested that method on this comment to see what it will look like:

[SaptakS]

I think we can also remove the "Release steps" section from readme https://github.com/lockdown-systems/cyd?tab=readme-ov-file#making-releases, since that is probably not something required by contributors.

[micahflee]

I'm working on manually removing sensitive data from all issues now. Going forward, let's not add anything sensitive to this git repo. Done! I've gone through all the old issues and removed all sensitive info.

[micahflee]

I've started working on a PR to address this #368

This PR will include:

• updating all of the docs (README.md, DEVELOPMENT.md, etc.) to make it reasonable for an open source project
• creating "open" mode so Cyd can work without the server -- this will require some development to support
• adding a GPLv3 license
• adding a github contributor agreement, and maybe issue templates, etc.