book/05-distributed-git/sections/contributing.asc

It’s also a good idea to use the imperative present tense in these messages. In other words, use commands. Instead of “I added tests for” or “Adding tests for,” use “Add tests for.” Here is a template originally written by Tim Pope:

The book do not always follow its own recommondation about proper git commit messages.

The secction "Committing Your Changes" should point a reference to this recommondation section.

Errata:
book/02-git-basics/sections/viewing-history.asc
changed the version number => Change the version number
removed unnecessary test => Remove unnecessary test

book/03-git-branching/sections/nutshell.asc
Fixed bug #1328 => Fix bug #1328
made a change => make a change
made other changes => make other changes

There are different case in two examples:
34ac2 Fixed bug #1328
34ac2 fixed bug #1328

book/03-git-branching/sections/basic-branching-and-merging.asc
added a new footer => add a new footer
finished the new footer => finish the new footer
fixed the broken email address => fix the broken email address

book/03-git-branching/sections/remote-branches.asc
forgot the brackets => add forgotten brackets
deploying index fix => deploy index fix
trying something new => try something new

book/05-distributed-git/sections/contributing.asc
made the ls-tree function recursive => make the ls-tree function recursive

book/05-distributed-git/sections/maintaining.asc
seeing if this helps the gem => see if this helps the gem
updated the gemspec to hopefully work better => update the gemspec to hopefully work better

This is all I have for now after gotten to page 153 (PDF v2.1.33).