Added Chapter 18

[lehonma]

This is a rough conversion from DOCX.

[jonasmalacofilho]

• [x] table notes (depends on #25)
• [x] figure and table size adjustments

[jonasmalacofilho]

We apparently hit a LFS issue with this maintainer commit to a fork. : /

[jonasmalacofilho]

LFS issue bypassed... Some idea why it failed, but no idea why it worked before!

[jonasmalacofilho]

We still need to fix figure/table sizes.

Besides that, the history of this needs to be rewritten (ideally when otherwise ready for the merge) to remove any EMF/GIF files from the non-LFS history.

A quick example of one way to do it on the CLI:

# checkout the PR branch
git checkout Chapter18
# create and checkout a copy
git checkout -b temp-chapter18-rebase-for-lfs-fix

# analyze the history to see which commits added EMF/GIF files
# search for EMF/GIF files being added (or remove) and take note of those commits
git log development..HEAD

# start a interactive rebase
# any commits that add (or modify) EMF/GIF files need to *edit*ed; all other can simply be *pick*ed
git rebase --interactive development

# depending on where you are on the rebase, you'll need to:
# a) ammend a commit so that it uses LFS for EMF/GIF
git commit --amend
# b) manually remove a (previously) deleted EMF/GIF file to fix a rebase conflict
# (since to git the LFS file and the non-LFS are different)
git rm guide/18-fare_systems/assets/image9.emf
git commit --amend
# c) let git continue with the rebase
git rebase --continue

# check the results
git log --oneline --decorate --graph development Chapter18 temp-chapter18-rebase-for-lfs-fix
# if all is well, reset the PR branch to the temporary branch
# BE CAREFUL to check what you're doing before the reset --hard
git checkout Chapter18
git reset --hard temp-chapter18-rebase-for-lfs-fix

An example of the resulting rebased branch exists in my fork: jonasmalacofilho/test-chapter18-rebased-for-lfs-fix.

[lehonma]

This chapter is ready for a rebase

[jonasmalacofilho]

ok, thanks

[lehonma]

My working-tree was rotten (heh), so I added my changes on pull request #81