add npm install instructions

[brunob]

Doc is always welcome, but i doubt on this, any thoughts @jieter ?

[jieter]

I'd say a single package manager should be enough, I think yarn users know that they can replace npm with yarn. Can we also use unpkg for leaflet-providers.js, avoiding the need to download it? That would be a nice improvement.

[brunob]

Can we also use unpkg for leaflet-providers.js, avoiding the need to download it? That would be a nice improvement.

Nice catch https://unpkg.com/browse/leaflet-providers@latest/leaflet-providers.js does the job ping @vincerubinetti

[vincerubinetti]

I've updated the branch. That unpkg link was incorrect, I fixed it. The yarn command is just there for copy/paste convenience but I removed it.

[jieter]

Looks good, thanks!