Add bilingual manual and localized docs routes

doc/manual/source/language/value/index.md

@@ -0,0 +1,20 @@
+# Value
+
+This chapter defines the kinds of values handled by the language.
+
+Primitive types are built-in constraints that values must satisfy, rather than ordinary data values.
+
+```dcdl
+name = String;
+retry = Int default 3;
+ratio = Float;
+enable = Bool default true;
+tags = [...String];
+```
+
+The primitive types are `String`, `Int`, `Float`, and `Bool`.
+`Unknown` is not a primitive type; it is the top abstract range containing every Decodal value. An `Unknown` without a concrete value or default cannot be materialized.
+An array is not a primitive type and is described as `[...T]` with a required element constraint.
+Links to each type specification are collected in the [manual contents](../../index.md).
+
+See [Constraints and Defaults](../constraints-and-defaults.md) for details about primitive types and constraint composition.