startup.py file not loaded on startup

## Issue

When starting renardo, the lib does not load the startup.py file, due to a wrong relative path setting.

### Error
```
Warning: '/home/user/.local/share/pipx/venvs/renardo/lib/python3.11/site-packages/renardo_lib/lib/Custom/startup.py' startup file not found.
```

## Expected behaviour

Loading the custom file in renardo_lib/Custom/startup.py

## Fix

Editing the file `renardo_lib/Settings/__init__.py` at the line 43 (remove the "`/lib`"):

```
FOXDOT_STARTUP_PATH = os.path.realpath(FOXDOT_ROOT + "/Custom/startup.py")
```

Unsure if there is a more elegant way to do this, but this is useful for temporary fixing the issue

EDIT: typo

Start by reading line 43 in renardo_lib/Settings/__init__.py and reproduce the startup warning when launching renardo. Check that the path resolves to renardo_lib/Custom/startup.py rather than the nonexistent nested lib path; done means the custom startup file loads without the warning.

Written by the indexing model from the issue text.