Add documentation for some Tuple operations

Author: anatoliykmetyuk

library/src/scala/Tuple.scala

@@ -33,9 +33,18 @@ sealed trait Tuple extends Any {
   inline def size[This >: this.type <: Tuple]: Size[This] =
     DynamicTuple.dynamicSize(this)
 
+  /** Given two tuples, `(A1, ..., An)` and `(B1, ..., Bn)`, returns a tuple
+   *  `((A1, B1), ..., (An, Bn))`. If the two tuples have different sizes,
+   *  the extra elements of the larger tuple will be disregarded.
+   */
   inline def zip[This >: this.type <: Tuple, T2 <: Tuple](t2: T2): Zip[This, T2] =
     DynamicTuple.dynamicZip(this, t2)
 
+  /** Called on a tuple `(A1, ..., An)`, returns a new tuple of type
+  *   `(F[A1], ..., F[An])`. Each element of this tuple is the result
+  *   of application of function `f` to the corresponding element of the
+  *   callee tuple.
+  */
   inline def map[F[_]](f: [t] => t => F[t]): Map[this.type, F] =
     DynamicTuple.dynamicMap(this, f)
 }
@@ -79,6 +88,10 @@ object Tuple {
     case h *: t => F[h] *: Map[t, F]
   }
 
+  /** Given two tuples, `(A1, ..., An)` and `(B1, ..., Bn)`, returns a tuple
+   *  `((A1, B1), ..., (An, Bn))`. If the two tuples have different sizes,
+   *  the extra elements of the larger tuple will be disregarded.
+   */
   type Zip[T1 <: Tuple, T2 <: Tuple] <: Tuple = (T1, T2) match {
     case (h1 *: t1, h2 *: t2) => (h1, h2) *: Zip[t1, t2]
     case (Unit, _) => Unit