docs(user): create printing and drawing howto

docs/index.rst

@@ -24,6 +24,7 @@ Concrete Framework's documentation
    :caption: How to
 
    user/howto/COMPILING_AND_EXECUTING.md
+   user/howto/PRINTING_AND_DRAWING.md
    user/howto/REDUCE_NEEDED_PRECISION.md
    user/howto/DEBUG_SUPPORT_SUBMIT_ISSUES.md
    user/howto/FAQ.md

docs/user/howto/PRINTING_AND_DRAWING.md

@@ -0,0 +1,49 @@
+# Printing and Drawing
+
+Sometimes, it can be useful to print or draw fhe circuits, we provide methods to just do that. Please read [Compiling and Executing](../howto/COMPILING_AND_EXECUTING.md) before reading further to see how you can compile your function into an fhe circuit.
+
+## Printing
+
+To print your circuit, you can do the following:
+
+<!--python-test:skip-->
+```python
+print(circuit)
+```
+
+## Drawing
+
+To draw your circuit, you can do the following:
+
+<!--python-test:skip-->
+```python
+drawing = circuit.draw()
+```
+
+This method will draw the circuit on a temporary PNG file and return the path to this file.
+
+To show the drawing, you can use the following code in a jupyter notebook.
+
+<!--python-test:skip-->
+```python
+from PIL import Image
+drawing = Image.open(circuit.draw())
+drawing.show()
+drawing.close()
+```
+
+Additionally, you can use the `show` option of the `draw` method to show the drawing with matplotlib. Beware that this will clear the matplotlib plots you have.
+
+<!--python-test:skip-->
+```python
+circuit.draw(show=True)
+```
+
+Lastly, you can save the drawing to a specific path like this:
+
+<!--python-test:skip-->
+```python
+destination = "/tmp/path/of/your/choice.png"
+drawing = circuit.draw(save_to=destination)
+assert drawing == destination
+```