Add doc to module helpers

src/module/helpers/mod.rs

@@ -1,17 +1,39 @@
+/*!
+ * Utility helpers for modules
+ */
+
 pub mod header;
 pub mod utils;
 
+/**
+ * Helpers for header specs
+ */
 pub mod spec {
     use storage::file::header::spec::FileHeaderSpec as FHS;
 
+    /**
+     * Helper to get a spec for a Key-Value for a named text:
+     *
+     *  { '<name>': "<Text>" }
+     */
     pub fn named_text(name: &str) -> FHS {
         FHS::Key { name: String::from(name), value_type: Box::new(FHS::Text) }
     }
 
+    /**
+     * Helper to get a spec for a Key-Value for a named array:
+     *
+     *  { '<name>': [ "<Text>", ...] }
+     */
     pub fn named_text_array(name: &str) -> FHS {
         FHS::Key { name: String::from(name), value_type: Box::new(text_array()) }
     }
 
+    /**
+     * Helper to get a spec for Array<Text>:
+     *
+     *  [ "<Text>", ...]
+     */
     pub fn text_array() -> FHS {
         FHS::Array { allowed_types: vec![FHS::Text] }
     }