Readme: fix link and add brief description

Update README.md

README.md

@@ -1,5 +1,41 @@
 # DINA
 
-[![Stable](https://img.shields.io/badge/docs-stable-blue.svg)](https://greimel.github.io/DINA.jl/stable)
-[![Dev](https://img.shields.io/badge/docs-dev-blue.svg)](https://greimel.github.io/DINA.jl/dev)
+[![Stable](https://img.shields.io/badge/docs-stable-blue.svg)](https://greimel.github.io/DINA.jl/stable/)
+[![Dev](https://img.shields.io/badge/docs-dev-blue.svg)](https://greimel.github.io/DINA.jl/dev/)
 [![Build Status](https://github.com/greimel/DINA.jl/workflows/CI/badge.svg)](https://github.com/greimel/DINA.jl/actions)
+
+This package uses DataDeps.jl to download the US distributional national accounts (DINA) dataset from [Gabriel Zucman's website](http://gabriel-zucman.eu/usdina/). The data are downloaded in bulk (>1GB) and stored in `.julia/datadeps/dina/`.
+
+The dataset is described in Piketty, T, E. Saez and G. Zucman: **Distributional National Accounts: Methods and Estimates for the United States**, *Quarterly Journal of Economics, 2018, 133 (2): 553-609.*
+
+The variables are described in [the codebook at Gabriel Zucman's website](http://gabriel-zucman.eu/files/PSZCodebook.pdf).
+
+## Usage
+
+Load the DINA micro-data by year
+
+```julia
+using DINA, DataFrames
+
+tbl = get_dina(1980)
+df80 = DataFrame(tbl)
+```
+
+or load a quantile-year panel (takes about 1-2 minutes for 1962--2019).
+
+```julia
+using DINA
+
+inc = :peinc
+wgt = :dweght
+
+dbt_var = [:ownermort, :rentalmort, :nonmort, :hwdeb]
+var = [[:fiinc, :fninc, :ptinc, inc, :poinc, :ownerhome, :rentalhome]; dbt_var]
+byvar = inc # compute deciles of `:peinc`
+
+df = dina_quantile_panel(var, byvar, 10)
+```
+
+This is a picture you can produce using `df`. Have a look at the documentation for the full code.
+
+![](https://greimel.github.io/DINA.jl/stable/fig_dbt.svg)

docs/src/index.md

@@ -8,11 +8,11 @@ CurrentModule = DINA
 
 ```
 
-This package uses DataDeps.jl to download the US distributional national accounts (DINA) dataset from [Gabriel Zucman's website](http://gabriel-zucman.eu/usdina/). The data are downloaded in bulk (<1GB) and stored in `.julia/datadeps/dina/`.
+This package uses DataDeps.jl to download the US distributional national accounts (DINA) dataset from [Gabriel Zucman's website](http://gabriel-zucman.eu/usdina/). The data are downloaded in bulk (>1GB) and stored in `.julia/datadeps/dina/`.
 
 The dataset is described in Piketty, T, E. Saez and G. Zucman: **Distributional National Accounts: Methods and Estimates for the United States**, *Quarterly Journal of Economics, 2018, 133 (2): 553-609.*
 
-The variables are described in this document [the codebook at Gabriel Zucman's website](http://gabriel-zucman.eu/files/PSZCodebook.pdf).
+The variables are described in [the codebook at Gabriel Zucman's website](http://gabriel-zucman.eu/files/PSZCodebook.pdf).
 
 ## Getting the micro data for a year