Produce and publish binaries for the asciidoctor-pdf executable

[ggrossetie]

Using pkg:

$ pkg package.json             
> pkg@4.4.0
> Targets not specified. Assuming:
  node10-linux-x64, node10-macos-x64, node10-win-x64
> Warning Malformed requirement for 'requirePath'
  /home/guillaume/workspace/opensource/asciidoctor/asciidoctor-pdf.js/lib/document/templates.js
> Warning Cannot include directory %1 into executable.
  The directory must be distributed with executable as %2.
  node_modules/puppeteer/.local-chromium
  path-to-executable/puppeteer
> Warning Failed to make bytecode node10-x64 for file /snapshot/asciidoctor-pdf.js/node_modules/mathjax-full/components/src/node-main/node-main.js
> Warning Failed to make bytecode node10-x64 for file /snapshot/asciidoctor-pdf.js/node_modules/mathjax-full/components/src/core/core.js
> Warning Failed to make bytecode node10-x64 for file /snapshot/asciidoctor-pdf.js/node_modules/mathjax-full/components/src/adaptors/liteDOM/liteDOM.js
> Warning Failed to make bytecode node10-x64 for file /snapshot/asciidoctor-pdf.js/node_modules/mathjax-full/components/src/node-main/node-main.js
> Warning Failed to make bytecode node10-x64 for file /snapshot/asciidoctor-pdf.js/node_modules/mathjax-full/components/src/core/core.js
> Warning Failed to make bytecode node10-x64 for file /snapshot/asciidoctor-pdf.js/node_modules/mathjax-full/components/src/adaptors/liteDOM/liteDOM.js
> Warning Failed to make bytecode node10-x64 for file C:\snapshot\asciidoctor-pdf.js\node_modules\mathjax-full\components\src\node-main\node-main.js
> Warning Failed to make bytecode node10-x64 for file C:\snapshot\asciidoctor-pdf.js\node_modules\mathjax-full\components\src\core\core.js
> Warning Failed to make bytecode node10-x64 for file C:\snapshot\asciidoctor-pdf.js\node_modules\mathjax-full\components\src\adaptors\liteDOM\liteDOM.js

As you can see there's a few warnings but overall it's working if you define the PUPPETEER_EXECUTABLE_PATH environment variable.

For instance:

$ PUPPETEER_EXECUTABLE_PATH=/usr/bin/chromium-browser ./asciidoctor-pdf-linux examples/document/basic-example.adoc

[thom4parisot]

There are a few hints in vercel/pkg#204

[ggrossetie]

There are a few hints in vercel/pkg#204

Thanks!
I've read a few comments but I think it's OK to point to an external Chromium binary.
We could probably try to automatically resolve the executable path depending on the operating system if PUPPETEER_EXECUTABLE_PATH is not defined.