docs: write the readme

README.md

@@ -1,3 +1,33 @@
 # gee-sphinx-inventory
 
-The code used to generate the sphinx inventory of the GEE objects
+The code used to generate the sphinx inventory of the GEE objects.
+
+## Usage
+
+This repository is generating and storing the Sphinx inventory of the GEE objects.
+The inventory is generated by the `generate_inventory.py` script.
+The script is using the `ee` module to get the list of the objects and their methods.
+The inventory is stored in the `inventory/earthengine-api.inv` file.
+The `inventory.json` file is used by the `sphinx` to generate the documentation.
+
+To link Earth Engine object in your sphinx documentation, add the following to your `conf.py` file:
+
+```python
+intersphinx_mapping = {
+    'ee': (
+        "https://developers.google.com/earth-engine/apidocs",
+        "https://raw.githubusercontent.com/gee-community/sphinx-inventory/refs/heads/main/inventory/earthengine-api.inv"
+    ),
+}
+```
+
+Then you can use the `:py:class:'ee.Image'` role to link the Earth Engine object in your Sphinx files.
+It will appear as [`ee.Image`](https://developers.google.com/earth-engine/apidocs/ee-image) in the built documentation.
+
+```rst
+
+> [!NOTE]
+> - To know more about `earthengine-api` read their documentation [here](https://developers.google.com/earth-engine)
+> - To know more about `sphinx` read their documentation [here](https://www.sphinx-doc.org/en/master/)
+> - To know more about `sphinx.ext.intersphinx` usage read their documentation [here](https://www.sphinx-doc.org/en/master/usage/extensions/intersphinx.html)
+```