Don't track build artefacts

[php1ic]

A lot of the files in the repo are created/modified when you compile the main document. There is no need for them to be to be tracked as either they create very noisy commits, or you have to do additional work to revert these files back to their original state before committing, in which case they no longer match the document in it's latest state.

For example, if I change the title text of the first \part{} and recompile, I have made changes to 7 files

$ git status 
On branch master
Your branch is up to date with 'origin/master'.

Changes not staged for commit:
  (use "git add/rm <file>..." to update what will be committed)
  (use "git checkout -- <file>..." to discard changes in working directory)

	modified:   Data Engineering Cookbook.aux
	modified:   Data Engineering Cookbook.log
	modified:   Data Engineering Cookbook.out
	modified:   Data Engineering Cookbook.pdf
	deleted:    Data Engineering Cookbook.synctex.gz
	modified:   Data Engineering Cookbook.tex
	modified:   Data Engineering Cookbook.toc

no changes added to commit (use "git add" and/or "git commit -a")

The important detail could easily be lost here.

Installs of texlive delete the .synctex.gz by default, unless you pass synctex=1 as an option to pdflatex.

I think a .gitignore with the following content will be a good place to start

# Ignore build artefacts
*.aux
*.log
*.lof
*.lot
*.toc
*.out
*.synctex.gz

This will keep commits, and PRs, clean and easier to follow.