Added documentation for scoped imports.

module.dd

@@ -363,6 +363,33 @@ void main()
                             // foo is not a member of io
 --------------
 
+<h3>Import Scoping</h3>
+
+    $(P Import declarations may be used at any scope. For example:)
+
+--------------
+void main() {
+  import std.stdio;
+  writeln("bar");
+}
+--------------
+
+    $(P The scope of imported symbols is the same as the scope of the import
+    declaration. Imported symbols may hide symbols from outer scopes.
+    For example:)
+
+--------------
+void main() {
+  void writeln(string) {}
+  void foo() {
+    import std.stdio;
+    writeln("bar"); // calls std.stdio.writeln
+  }
+  writeln("bar"); // calls main.writeln
+  std.stdio.writeln("bar");  // error, std is undefined
+}
+--------------
+
 <h3>Module Scope Operator</h3>
 
 	Sometimes, it's necessary to override the usual lexical scoping rules