qim3d installation check

https://www.notion.so/qim-dtu/v1-0-prep-Add-installation-check-to-the-docs-145bab83b2f9807caaf5e0f74beb4b98

docs/index.md

@@ -137,6 +137,16 @@ The latest stable version can be simply installed using `pip`. Open your termina
 !!! note
     The base installation of `qim3d` does not include deep-learning dependencies, keeping the library lighter for scenarios where they are unnecessary. If you need to use deep-learning features, you can install the additional dependencies by running: **`pip install qim3d['deep-learning']`**
 
+After completing the installation, you can verify its success by running one or both of the following commands:
+
+    pip show qim3d
+
+or:
+
+    python -c "import qim3d; print(qim3d.__version__)"
+
+If either command displays information about the qim3d library, the installation was successful.
+
 ### Troubleshooting
 
 Here are some solutions for commonly found issues during installation and usage of `qim3d`.