Update README.md

Author: nicolaskruchten

README.md

@@ -6,10 +6,20 @@ Documentation and examples can be found at https://plotly.express/
 
 ## Installation
 
+Plotly Express is compatible with Python 3+ and Python 2.7.
+
+### Via `pip`
+
 Just running `pip install plotly_express` in your terminal should do it!
 
-Plotly Express is compatible with Python 3+ and Python 2.7.
+### Via `conda`
+
+You'll have to install from the `plotly` channel with `conda install -c plotly plotly_express`
 
 ### Running in JupyterLab
 
 Using Plotly Express in JupyterLab requires the [`plotly-extension`](https://github.com/jupyterlab/jupyter-renderers/tree/master/packages/plotly-extension) to be installed by running `jupyter labextension install @jupyterlab/plotly-extension`.
+
+## Troubleshooting
+
+Plotly Express depends on very recent versions of `plotly` and it's sometimes possible to get into a state where you have multiple versions of `plotly` installed (e.g. once with `pip` and once with `conda`) so be sure to check your version by running `plotly.__version__` in the same environment that you're having issues with `plotly_express`.