(doc) Added rustdoc for alloy module.
(doc) Added rustdoc for furnace module.
(doc) Added rustdoc for ingot module.
(doc) Added rustdoc for iron module.
(doc) Added rustdoc for request module.
(doc) Added rustdoc for response module.
(doc) Fixed formatting in lib.rs
Merge pull request #36 from reem/doc/module-doc-comments

Added top-level rustdoc for all modules.