Improve typography (#120)

* Add unbreakable space before a reference or a citation

avoids ref to be put on next line or page...

* Add unbreakable space between I and verb

* Remove spacing before footnotes

Also moved it before the final sentence dots in many cases... might need
a review of what is best.  But this is a safe default choice from an
esthetic point of view.

* Improve footnotes and punctuations

Reverse order/kerning especially with sans-serif version.

* Remove manual enumerate

* Fix wording in a citation.

Reads better that way and is shorter.

* Use emph instead of italics

1) Markup semantic not style
2) Will deal with various level of empahasis
3) Was a mix of \it and \textit

* Fix usage of quotes

Also replaced some of then by \emph as it is (IMHO) more visually
pleasant.

* Captitalize before reference

* Correct dashes length

see here:
https://www.merriam-webster.com/words-at-play/em-dash-en-dash-how-to-use

* Remove space before label and homogenize caption

Apparently it can create a wrong reference, if notthing else shuts
texcheck up and cost nothing... so let's do it.

While at it adding a dot at the end of each caption.

* Add missing empty line before signature in preface

* Add a static checker target to makefile

Shall help prevent adding mistakes in new versions

book/book.tex

@@ -24,6 +24,9 @@
     \renewcommand{\familydefault}{\sfdefault}
 \fi
 
+% Kerning in footnotes
+\usepackage{fnpct}
+
 % References
 \usepackage[backend=biber]{biblatex}
 \addbibresource{references.bib}
@@ -110,19 +113,19 @@
 \chapter{Bread types}
 \input{bread-types/bread-types}
 
-\chapter{Wheat sourdough}
+\chapter{Wheat sourdough}%
 \label{chapter:wheat-sourdough}
 \input{wheat-sourdough/wheat-sourdough}
 
-\chapter{Non wheat sourdough}
+\chapter{Non wheat sourdough}%
 \label{chapter:non-wheat-sourdough}
 \input{non-wheat-sourdough/non-wheat-sourdough}
 
-\chapter{Baking}
+\chapter{Baking}%
 \label{chapter:baking}
 \input{baking/baking}
 
-\chapter{Storing bread}
+\chapter{Storing bread}%
 \label{chapter:storing-bread}
 \input{storing-bread/storing-bread}