Summarizes the git log output.

# To view a summary of all the commits made, grouped alphabetically by author name:
git shortlog

# To view a summary of all the commits made, sorted by the number of commits made:
git shortlog -n

# To view a summary of all the commits made, grouped by the commiter identities (name and email):
git shortlog -c

# To view a summary of the last 5 commits (i.e. specify a revision range):
git shortlog HEAD~5..HEAD