README.md: update and add example

Author: veghdev

README.md

@@ -1,2 +1,34 @@
-# write-npmstat
+# About The Project
+
 write-npmstat makes it easy to collect, filter and save npm statistics to csv files.
+
+# Installation
+
+write-npmstat requires `npm-stat-api`, `enum`, `csv-writer` and `csv-parser` packages.
+
+```sh
+npm install write-npmstat
+```
+
+# Usage
+
+```js
+const WriteNpmStat = require("write-npmstat");
+
+packageName = "npm-stat-api"
+outDir = "stats/npm-stat-api"
+const writenpmstat = new WriteNpmStat(packageName, outDir);
+
+writenpmstat.datePeriod = "month";
+writenpmstat.writeNpmStat("2022", "2022-03");
+```
+
+# Contact
+
+Join our [discussions](https://github.com/veghdev/write-npmstat/discussions) page if you have any questions or comments.
+
+# License
+
+Copyright © 2022.
+
+Released under the [Apache 2.0 License](https://github.com/veghdev/write-npmstat/blob/main/LICENSE).