docs: Clarify Map

Author: epage

src/map.rs

@@ -1,4 +1,7 @@
+/// The backing store for [`Config`][crate::Config]
+pub type Map<K, V> = InternalMap<K, V>;
+
 #[cfg(not(feature = "preserve_order"))]
-pub type Map<K, V> = std::collections::HashMap<K, V>;
+type InternalMap<K, V> = std::collections::HashMap<K, V>;
 #[cfg(feature = "preserve_order")]
-pub type Map<K, V> = indexmap::IndexMap<K, V>;
+type InternalMap<K, V> = indexmap::IndexMap<K, V>;

src/source.rs

@@ -13,8 +13,8 @@ use crate::value::{Value, ValueKind};
 pub trait Source: Debug {
     fn clone_into_box(&self) -> Box<dyn Source + Send + Sync>;
 
-    /// Collect all configuration properties available from this source and return
-    /// a Map.
+    /// Collect all configuration properties available from this source into
+    /// a [`Map`].
     fn collect(&self) -> Result<Map<String, Value>>;
 
     /// Collects all configuration properties to a provided cache.