Added braket to template (#48)

Author: jarkabaker

src/template.latex

@@ -8,7 +8,7 @@ $if(linestretch)$
 \usepackage{setspace}
 \setstretch{$linestretch$}
 $endif$
-\usepackage{cancel}
+\usepackage{braket,cancel}
 \usepackage{amssymb,amsmath}
 \usepackage{ifxetex,ifluatex}
 \usepackage{fixltx2e} % provides \textsubscript