Add .gitignore and remove generated files

.gitignore

.ipynb_checkpoints/Apples_and_Oranges-checkpoint.ipynb

.ipynb_checkpoints/Argumentation_Theory-checkpoint.ipynb

.ipynb_checkpoints/Bridges_Puzzle-checkpoint.ipynb

.ipynb_checkpoints/Cheryls_Birthday-checkpoint.ipynb

.ipynb_checkpoints/N_Queens-checkpoint.ipynb

...eckpoints/ProB_Jupyter_Notebook_Overview-checkpoint.ipynb

notebook.tex

output_78_0.pdf

output_78_0.svg

output_79_0.pdf

output_79_0.svg