feat: added "One Time Secret"

[nktnet1]

Note

• One Time Secret is not the same as the existing OTS project
• Website URL and Demo URL are the same - perhaps the demo url should be removed?
• Related Software URL is just a section of the README already linked in the Source Code Url. Can be omitted?
• There is also the docs URL, but doesn't fit anywhere in the template: https://docs.onetimesecret.com

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[Rabenherz112]

Pending further thoughts from reviewers.

[kokomo123]

As far as i can tell, LGTM pending further thoughts from collaborators..