Okay sorry, I looked at electron. If you want a local copy you can try https://gethttpsforfree.com/ it's completely client sided, you can save the html file and use whenever. You have to generate your own keys and CSR though
I just ran through the process, and it worked very smoothly. No hick-ups, it just worked. SSLlabs reports an A. Very awesome.
Thanks. SSL should always have been this easy. I used the let's encrypt client when it came out and it took 3 hours to install on my server requiring root access. I couldn't get a client working on windows as well so for people without root access to their server they can't even really get a certificate. I paid for my certificates before this and it takes at least 30 minutes. This literally takes seconds once you know your FTP or know how to manually do it.