Feat: add slicing words

tests/forth/comparison.rs

@@ -196,21 +196,21 @@ fn ifelse_false() {
 }
 
 #[test]
-fn pick_first() {
-    expect_int("{ 10 } { 20 } { 30 } 0 pick", 10);
+fn select_first() {
+    expect_int("{ 10 } { 20 } { 30 } 0 select", 10);
 }
 
 #[test]
-fn pick_second() {
-    expect_int("{ 10 } { 20 } { 30 } 1 pick", 20);
+fn select_second() {
+    expect_int("{ 10 } { 20 } { 30 } 1 select", 20);
 }
 
 #[test]
-fn pick_third() {
-    expect_int("{ 10 } { 20 } { 30 } 2 pick", 30);
+fn select_third() {
+    expect_int("{ 10 } { 20 } { 30 } 2 select", 30);
 }
 
 #[test]
-fn pick_preserves_stack() {
-    expect_int("5 { 10 } { 20 } 0 pick +", 15);
+fn select_preserves_stack() {
+    expect_int("5 { 10 } { 20 } 0 select +", 15);
 }