Add let to README. #12

README.md

@@ -13,7 +13,7 @@ class](https://www.dabeaz.com/sicp.html).
 `smallscheme` is not a complete R7RS Scheme (or R5RS for that matter) -- it implements
 everything needed to follow along in
 [SICP](https://en.wikipedia.org/wiki/Structure_and_Interpretation_of_Computer_Programs)
-up to page **63**.  `smallscheme` is very lightweight and can be
+up to page **68**.  `smallscheme` is very lightweight and can be
 installed on any Python 3 installation as follows:
 
 # Install
@@ -86,6 +86,7 @@ There are also two simple functions used in the Scheme-language tests: `is` and
     define
     if
     lambda
+    let
     or
     quote