docs: update README

README.md

@@ -1,3 +1,44 @@
 # Arabic Wiki Dataset
 
-This dataset is extracted using [wikiextractor](https://github.com/attardi/wikiextractor) tool, from [Wikipedia Arabic pages](https://dumps.wikimedia.org/arwiki/).
+## Dataset Summary
+This dataset is extracted using [`wikiextractor`](https://github.com/attardi/wikiextractor) tool, from [Wikipedia Arabic pages](https://dumps.wikimedia.org/arwiki/).
+
+## Supported Tasks and Leaderboards
+Intended to train **Arabic** language models on MSA (Modern Spoken Arabic).
+
+## Dataset Structure
+The dataset is structured into 2 folders:
+- `arwiki_20211213_txt`: dataset is divided into subfolders each of which contains no more than 100 documents.
+- `arwiki_20211213_txt_single`: all documents merged together in a single txt file.
+
+## Dataset Statistics
+
+#### Extracts from **December 13, 2021**:
+
+| documents | vocabulary | words |
+| --- | --- | --- |
+| 1,136,455 | 5,446,560 | 175,566,016 |
+
+## Usage
+Load all dataset from the single txt file:
+```python
+load_dataset('CALM/arwiki', 
+              data_files='arwiki_2021_txt_single/arwiki_20211213.txt')
+
+# OR with stream
+
+load_dataset('CALM/arwiki', 
+              data_files='arwiki_2021_txt_single/arwiki_20211213.txt', 
+              streaming=True)
+```
+Load a smaller subset from the individual txt files:
+```python
+load_dataset('CALM/arwiki', 
+              data_files='arwiki_2021_txt/AA/arwiki_20211213_1208.txt')
+
+# OR with stream
+
+load_dataset('CALM/arwiki', 
+              data_files='arwiki_2021_txt/AA/arwiki_20211213_1208.txt', 
+              streaming=True)
+```