chore(release): phd-thesis 0.12.6

editing(abstract): Optimise wording
editing(introduction): Missing opening
chore(bib): Update bibliography
chore(preamble): Include new symbol packages
fix(final check): This fixes references and consistency

version.tex

@@ -1 +1 @@
-\providecommand{\version}{0.12.5}
+\providecommand{\version}{0.12.6}