added a torus matrix file for the examples directory

[KoyanoBunsho]

Dear Code Maintainers

I hope this message finds you well.
I am Bunsho Koyano, currently in my second year of Ph.D. studies at The University of Tokyo, where I specialize in Computer Science. I recently came across the CHomP repository and was impressed by its capabilities. I am eager to integrate it into my upcoming projects.

However, I encountered an issue: the 'torus.mat' file appears to be missing from the examples directory, preventing me from running the following command:

chomp-matrix ./examples/torus.mat

To resolve this, I created the 'torus.mat' file in the examples directory with the following content:

0
0 0 0
0 1 0
1
0 0 0
1 0 0

After the adjustment, I successfully executed the command, which yielded the following output:

Betti Numbers: 1 2 1 

Thank you so much for considering my request. Your approval and subsequent merge of this pull request would be greatly appreciated.

Best regards

Bunsho Koyano