Creating a basic SpanDeX project

There are two ways of creating a SpanDeX project:

either you want to create it in a new directory, in which case you can run
```
spandex init <project_name>
```
or you already have in directory that you want to setup for a SpanDeX project, in which case you can simply run
```
spandex init
```

This will generate the default configuration file spandex.toml and an initial main.dex file.

To compile your files into a PDF, you can simply run

spandex build

SpanDex book