Reinstate install from Git

[ddbeck]

Summary

Reinstate the option to install BCD from Git. This is useful to, for example, run analysis against the data of a BCD PR, before it's merged and released.

Test results and supporting details

1. Run npm install git+https://github.com/mdn/browser-compat-data.git and attempt to import or require BCD. 😢
2. Run npm install git+https://github.com/ddbeck/browser-compat-data.git#installable-from-HEAD and attempt to import or require BCD. 😄

Related issues

Regress originated at #16593.

[ddbeck]

@queengooborg I'm very confused by your comment. What build artifacts are being tracked by Git here? I haven't touched .gitignore nor have I checked in data.json. It's not clear to me how my changes would require such. Could you spell this out for me?

[queengooborg]

Oh...I'm sorry, I misread what file is being touched. I thought you were updating .gitignore, not .npmignore.

Misread the changes this PR is performing

[queengooborg]

Okay, now that I've properly read what exactly this PR is doing, this is LGTM. Apologies for the previous review, I panicked because I thought that .gitignore was being updated, not .npmignore.

Small nit: we could actually probably just remove .npmignore altogether? Since we deploy from the build/ folder, the .npmignore doesn't really have any effect.

[ddbeck]

Thanks, @queengooborg!

Small nit: we could actually probably just remove .npmignore altogether? Since we deploy from the build/ folder, the .npmignore doesn't really have any effect.

I'll put it on my to do list to experiment with this a bit. IIRC, in the absence of a .npmignore, npm uses .gitignore. We might still need an empty .npmignore, for the changes in this PR to continue to work.