docs: improve readme

README.md

@@ -5,13 +5,22 @@ the spread and effect of COVID-19. The goal is to provide a central place where
 data, analysis, and discussion can be conducted and shared by a global community
 struggling to make sense of the current public health emergency.
 
-The project includes simple tools that make it very easy to work with the
-heterogeneous case data from various sources using common code. For a simple
-example, have a look at the [Global and Regional COVID-19 summary
+The main goal is not to create another dashboard, or collection of dashboards, for
+that matter. There are already many excellent ones available, for example, on
+https://covid19dashboards.com.
+
+The goal here is different: aggregate data from multiple
+public sources, standardize the data formats, and make the data around COVID-19 easy to
+work with. Rather than presenting answers to our questions, we want to make it easy for
+you to explore the data, and formulate and answer your own questions. Some questions
+can be answered by looking at just one data source, but many cannot. And it may be
+worthwhile to run an analysis initially developed against one data source against another.
+This project aims to make it possible, and hopefully even easy, to do these things.
+For a simple example, have a look at the [Global and Regional COVID-19 summary
 notebook](https://renkulab.io/projects/covid-19/covid-19-public-data/files/blob/runs/dataset_summary.run.ipynb).
 
-For each data source, we provide a summary notebook with interactive figures
-that can be used as starting points for further exploration:
+For each data source, we provide a simple summary notebook with interactive
+figures:
 
 * [Summary of global data from from JHU CSSE](https://renkulab.io/projects/covid-19/covid-19-public-data/files/blob/runs/Dashboard.run.ipynb)
 * [Global data from from ECDC](https://renkulab.io/projects/covid-19/covid-19-public-data/files/blob/runs/covid-19-ecdc.run.ipynb)