Julia adding package from github

I want to install the following package from github. I tried using the following command in my environment to install

(nlpEnvJl) pkg> add "https://github.com/yeesian/LeafletJS.jl/tree/master/src"

But I get the following error,

ERROR: could not find project file in package at https://github.com/yeesian/LeafletJS.jl maybe subdir needs to be specified

Any ideas on how I can get installed? Do I have to clone it first to my local repo? If so how do I install from local path?

CheersThanks in advance