Added public files

Roughly added all public files. Probably missed some, though.
diff --git a/doc/efun/acos b/doc/efun/acos
new file mode 100644
index 0000000..2487958
--- /dev/null
+++ b/doc/efun/acos
@@ -0,0 +1,8 @@
+SYNOPSIS
+        float acos(float)
+
+BESCHREIBUNG
+        Liefert der Arkuskosinus des Argumentes.
+
+SIEHE AUCH
+        sin(E), asin(E), cos(E), tan(E), atan(E), atan2(E)