message: Add language reference
diff: @@ -41,7 +41,7 @@ export type Value = number | boolean;
  /**
  * An instruction that places a literal value into a variable.
  */
  -export interface Const {
  +export interface Constant {
  op: "const";
  value: Value;
  dest: Ident;
  @@ -57,12 +57,12 @@ export type Operation = EffectOperation | ValueOperation;
  * Instructions can be operations (which have arguments) or constants (which
  * don't). Both produce a value in a destination variable.
  */
  -export type Instruction = Operation | Const;
  +export type Instruction = Operation | Constant;
  /**
  * Both constants and value operations produce results.
  */
  -export type ValueInstruction = Const | ValueOperation;
  +export type ValueInstruction = Constant | ValueOperation;
  /**
  * The valid opcodes for value-producing instructions.
  