📝 Add docs for debugging

docs/tutorial/debugging.md

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+You can connect the debugger in your editor, for example with Visual Studio Code or PyCharm.
+
+## Call `uvicorn`
+
+In your FastAPI application, import and run `uvicorn` directly:
+
+```Python hl_lines="1 15"
+{!./src/debugging/tutorial001.py!}
+```
+
+### About `__name__ == "__main__"`
+
+The main purpose of the `__name__ == "__main__"` is to have some code that is executed when your file is called with:
+
+```bash
+python myapp.py
+```
+
+but is not called when another file imports it, like in:
+
+```Python
+from myapp import app
+```
+
+#### More details
+
+Let's say your file is named `myapp.py`.
+
+If you run it with:
+
+```bash
+python myapp.py
+```
+
+then the internal variable `__name__` in your file, created automatically by Python, will have as value the string `"__main__"`.
+
+So, the section:
+
+```Python
+    uvicorn.run(app, host="0.0.0.0", port=8000)
+```
+
+will run.
+
+---
+
+This won't happen if you import that module (file).
+
+So, if you have another file `importer.py` with:
+
+```Python
+from myapp import app
+
+# Some more code
+```
+
+in that case, the automatic variable inside of `myapp.py` will not have the variable `__name__` with a value of `"__main__"`.
+
+So, the line:
+
+```Python
+    uvicorn.run(app, host="0.0.0.0", port=8000)
+```
+
+will not be executed.
+
+## Run your code with your debugger
+
+Because you are running the Uvicorn server directly from your code, you can call your Python program (your FastAPI application) directly form the debugger.
+
+---
+
+For example, in Visual Studio Code, you can:
+
+* Go to the "Debug" panel.
+* "Add configuration...".
+* Select "Python"
+* Run the debugger with the option "`Python: Current File (Integrated Terminal)`".
+
+It will then start the server with your **FastAPI** code, stop at your breakpoints, etc.
+
+Here's how it might look:
+
+<img src="/img/tutorial/debugging/image01.png">