Add suggestions for citation style and sorting=none as default

Very many student theses at LiU e-press use the default settings for
citation style, thinking this is the only choice LaTeX gives them.

The problem is that the style is numeric [1] but sorted by author name
instead of by order of appearance.

This commit adds a default sorting=none which makes the sorting by
appearance and lists a few suggestions for citation styles.

settings.tex

@@ -30,7 +30,22 @@
 %% 
 %%% Code:
 
-\usepackage[backend=biber,hyperref]{biblatex}
+%% To the author: Choose a citation style. Which one depends on your field of study.
+%% Ask your supervisor or examiner if you are uncertain.
+
+%% Good options for the style include for example:
+%% APA: style=authoryear + \DeclareDelimFormat{nameyeardelim}{\addcomma\space}
+%% Hardvard: style=authoryear
+%% IEEE: style=ieee
+%% Numeric: style=numeric,sorting=none  (like IEEE but with full names in the bibliography)
+%% Most other styles
+%%%
+%% NOTE: You may need to add more changes to fully conform to a citation style
+%% (making certain elements in italics, etc).
+
+%% The default is very bad (numeric style sorted alphabetically instead of by appearance).
+
+\usepackage[backend=biber,style=numeric,sorting=none,hyperref]{biblatex}
 %% To set the font of your thesis, use the \setmainfont{} command,
 %% surrounded with \ifxetex if you want to switch between xelatex and pdflatex
 \ifxetex