docs README updt

Author: Zippo00

docs/README.md

@@ -15,4 +15,12 @@
    make -C docs/source html
    ```
 
-   The HTML is created in the `docs/source/_build/html` directory.
+   The HTML is created in the `docs/source/_build/html` directory.
+
+## Generating documentations from source code
+
+1. While in root dir, run:
+
+   ```console
+   sphinx-apidoc -o path/to/target/dir avise
+   ```