added uploader-info.md

doc/uploader-info.md

+# elk-parser
+
+## Main file
+
+The main file is INFO.OUT. The parsing starts from this one and it fails if it is not present.
+
+## Other files coming from a ground-state calculation
+
+ The following files must be in the same folder as INFO.OUT:
+
+ * TDOS.OUT: density of states.
+ * EIGVAL.OUT: eigenvalues.
+