multiple html files as input fail to be bundled

[symful]

Describe the bug A clear and concise description of what the bug is.

Unable to serve or build with more than 1 HTML file as input.

Though, it works with just one HTML file.

To Reproduce Steps to reproduce the behavior:

git clone https://github.com/NekoMaru76/x-go
cd x-go
deno task build
deno task build_lib
deno task build_public

Expected behavior A clear and concise description of what you expected to
happen.

I expected it will work with multiple HTML files as input.

Is this packup bug or esbuild?

Screenshots If applicable, add screenshots to help explain your problem.