Why did you decide to make this a site rather than a desktop app?
This is a private database as I see it, so there is no need for it to be online. And keeping it offline would be good for privacy, and would make it easy for anyone to download and install, rather than the more complex install needed for a web application (or letting someone else host and sacrificing privacy).
Because I just know web technologies. Also, because having a web app will allow me to create an API, which will allow to use a mobile app for this, which totally makes sense.
If you care about the privacy, you can also host this yourself :-D
This is a private database as I see it, so there is no need for it to be online. And keeping it offline would be good for privacy, and would make it easy for anyone to download and install, rather than the more complex install needed for a web application (or letting someone else host and sacrificing privacy).