A simple HTML web form.
Check out the live demo here.
Please note that the demo form intentionally give out 405 errors. This is to prevent email spamming. It works if you host it on a standard host, but Github Pages doesn't support php.
Fork the repo. Change the $email_to = "youremail@mail.com"; in the php file to your email address to get the form submissions sent to you.
Download the forked repo. Choose which form you want, and place that form and the php file into your website public folder.
Note that the form is designed to be a separate page, but you can embed it if you want to.
Thats it! Make sure you have both the php file and the html file. If you have any issues, please feel free to create an issue.