Auto deploy preview with Netlify

[hong4rc]

I created a pull request hong4rc#3

and config

• Build command: gulp build
• Publish directory: build

Quick to detect error on UI

Do you want to use Netlify for preview, I going to create a pull request to build with Netlify (Netlify need build to a folder instead of index.html + build + assets + lib like your gh-pages)

[pcottle]

Wow it's really neat that you can browse the preview! This would be a nice addition to have.

What if we just build both to a folder for Netlify previews, and still build to the index.html file? we'll need the index.html file to still be there since that's what https://learngitbranching.js.org/ resolves to

[hong4rc]

My commit hong4rc/learnGitBranching@c2881e1 create index.html and copy assets + libs folder into build folder if process.env.CI is true.

if process.env.CI is undefined, nothing change

[pcottle]

Oh yeah that should be an easy way to do it. Excited to see this PR!

[pcottle]

#933