Added information about activating the pipenv environments to the guide

Author: DavidJVitale

guide/01-getting-started/install-and-set-up.ipynb

@@ -20,7 +20,7 @@
     "  - [Install Using ArcGIS Pro Python Package Manager](#Install-using-ArcGIS-Pro-Python-Package-Manager)\n",
     "  - [Install Using the Python Command Prompt](#Install-using-Python-Command-Prompt)\n",
     "  - [Install Using Anaconda for Python Distribution](#Install-using-Anaconda-for-Python-Distribution)\n",
-    "  - [Install Using pip](#Install-using-pip)\n",
+    "  - [Install Using pip or pipenv](#Install-using-pipenv-or-pip)\n",
     "    - [Install without Dependencies](#Install-without-Dependencies)\n",
     " - [Upgrade the `arcgis` package](#Upgrade-the-arcgis-package)\n",
     "   - [ArcGIS Pro 2.1](#ArcGIS-Pro-2.1)\n",
@@ -120,19 +120,25 @@
     "\n",
     "### Install using pipenv or pip\n",
     "\n",
-    "[Pipenv](https://docs.pipenv.org/) is the official packaging tool for managing environments and installing packages from the [Python Package Index (PyPI)](https://pypi.python.org/pypi). To install the ArcGIS API for Python from PyPI in a new environment, open a terminal and enter the following command:\n",
+    "#### Pipenv\n",
+    "[Pipenv](https://docs.pipenv.org/) is the official packaging tool for managing environments and installing packages from the [Python Package Index (PyPI)](https://pypi.python.org/pypi). To install the ArcGIS API for Python from PyPI in a new environment, open a terminal in an empty directory and enter the following command:\n",
     "\n",
     "```\n",
     "pipenv install arcgis\n",
     "```\n",
     "\n",
+    "This will install the `arcgis` package and create a `Pipfile` in your current working directory. You can activate this environment by running '`pipenv shell`' in this directory. You can also run any command in this environment without activating it by running '`pipenv run {insert_command_here}`'. See [this guide](http://docs.python-guide.org/en/latest/dev/virtualenvs/#installing-packages-for-your-project) for more information. \n",
+    "\n",
+    "#### Pip\n",
+    "\n",
     "[Pip](https://pip.pypa.io/en/stable/) is the predecessor of pipenv, and can also be used to install packages from PyPI (but you must manage environments with seperate tools like [virtualenv](https://virtualenv.pypa.io/en/stable/)). To install the API with pip, open a terminal and enter the following command:\n",
     "    \n",
     "```\n",
     "pip install arcgis\n",
     "```\n",
     "\n",
-    "You should avoid mixing conda with pipenv/pip: they are completely seperate package managers. It is recommended that you use conda to install the API if you are a beginner user. Read more about the differences [here](https://stackoverflow.com/questions/20994716/what-is-the-difference-between-pip-and-conda) and [here](https://docs.pipenv.org/).\n",
+    "#### Disclaimer\n",
+    "You should avoid mixing conda with pipenv/pip: they are completely seperate package managers. It is recommended that you use conda to install the API if you are a beginner user. Read more about the differences [here](https://stackoverflow.com/questions/20994716/what-is-the-difference-between-pip-and-conda) and [here](http://docs.python-guide.org/en/latest/dev/virtualenvs/).\n",
     "\n",
     "> Note: when installing the ArcGIS API for Python with pipenv/pip, some dependencies may require Microsoft Visual C++ 14.0. If you see any errors related to this, either install the Microsoft Visual C++ tools or install the API without dependencies.\n",
     "\n",