Added public files

Roughly added all public files. Probably missed some, though.
diff --git a/doc/efun/negate b/doc/efun/negate
new file mode 100644
index 0000000..b1f0bdf
--- /dev/null
+++ b/doc/efun/negate
@@ -0,0 +1,6 @@
+SYNOPSIS
+        int negate(int arg);
+        float negate(float arg);
+
+BESCHREIBUNG
+        Liefert den negativen Wert von <arg>.