format: an HTML file can be a fragment instead of a whole page - #89

cannot use "this build is missing its build tags, and without them the AVIF encoder reads past the end of a buffer and takes the process down. Build with -tags \"$(cat .github/build-tags)\", or see the install section of README.md" (untyped string constant "this build is missing its build tags, and without them the AVIF enco...) as buildWithoutTheNoasmTag value in variable declaration