Most likely a combination of asciinema https://asciinema.org/ https://asciinema.org/ and https://github.com/cirocosta/asciinema-edit https://github.com/cirocost

Most likely a combination of asciinema https://asciinema.org/ https://asciinema.org/ and https://github.com/cirocosta/asciinema-edit https://github.com/cirocosta/asciinema-edit (You can do it by hand as well, but the tools are easier). Use the Quantize and speed options