Fix letters + improvements for them. More fixes to come

examples/letter/letter.tex

@@ -0,0 +1,17 @@
+\documentclass[12pt,a4paper]{scrlttr2}
+
+\newcommand{\dir}{~/projects/latex} % IMPORTANT: No trailing slashes!
+\input{\dir/include.tex}
+\load{letter}
+
+% Subject
+\setkomavar{subject}{Test}
+\begin{document}\raggedright
+    \begin{letter}{Company \\ Name \\ Address \\ CH-Place}
+        \opening{Intro}
+
+            Test
+
+        \closing{Kind regards}
+    \end{letter}
+\end{document}