title: How to fix "'BROWSER' is not recognized as an internal or external command"?
body: <p>I am trying to run react-d3-tree-demo following this README.md at <a href="https://github.com/bkrem/react-d3-tree-demo" rel="noreferrer">https://github.com/bkrem/react-d3-tree-demo</a> </p>
  
  <p>After following the other steps, I got stuck on the second step of trying to run the app locally. The command line returns an error: "'BROWSER' is not recognized as an internal or external command, operable program or batch file," when I try to execute "npm run dev" in the react-d3-tree-demo directory that I cloned from the same repo. </p>
  
  <p>The README.md page instructs to run "npm run dev" in both the react-d3-tree and react-d3-tree-demo directories. I actually got an error when I did that command in the react-d3-tree directory where the command line said the linebreak was incorrect, but I went into the eslintrc.js file and added "'linebreak-style': 0," in the module exports which resolved the error. I've tried turning off my Avast antivirus software which was suggested on another page. Nothing has worked so far.</p>
  
  <p>To reproduce my problem:</p>
  
  <p>Demo:
  Clone this repo: git clone <a href="https://github.com/bkrem/react-d3-tree-demo.git" rel="noreferrer">https://github.com/bkrem/react-d3-tree-demo.git</a>
  cd react-d3-tree-demo
  Run yarn or npm install OR run bash ./setup.sh and skip to Running locally</p>
  
  <p>React-D3-Tree library:
  Inside the react-d3-tree-demo directory, clone the library: git clone <a href="https://github.com/bkrem/react-d3-tree.git" rel="noreferrer">https://github.com/bkrem/react-d3-tree.git</a>
  Run yarn or npm install</p>
  
  <p>Running locally:
  Set up 2 terminal windows, one in the react-d3-tree-demo directory, the other in react-d3-tree-demo/react-d3-tree (i.e. the sub-directory into which we cloned the library itself)
  Run yarn dev/npm run dev in each
  Any changes made to the demo app or the library should now automatically rebuild the library and reload the app with the fresh build (via nodemon).</p>
  
  <p>I expect the react app to open a page at localhost:8000 that looks like this: <a href="https://bkrem.github.io/react-d3-tree-demo/" rel="noreferrer">https://bkrem.github.io/react-d3-tree-demo/</a> however, I get a message from the command line that was detailed earlier. I'm not sure why they told me to clone react-d3-tree inside the demo, I'd appreciate any explanation of that also.</p>