Add more context to git diff

The -U flag specifies lines of context.

Source: How to get git diff with full context? - Stack Overflow

-U<n>, --unified=<n>
    Generate diffs with <n> lines of context instead of the usual three. Implies -p.

Source: git diff --help

Kind of like --context or -C for grep or git grep. Useful for reviewing SQL schema changes for tables with a lot of columns.