re-generate summary to include recent changes

SUMMARY.md

@@ -29,7 +29,7 @@
   * [A Flickr of Functional Programming](ch06.md#a-flickr-of-functional-programming)
   * [A Principled Refactor](ch06.md#a-principled-refactor)
   * [In Summary](ch06.md#in-summary)
-* [Chapter 07: Hindley-milner and Me](ch07.md)
+* [Chapter 07: Hindley-Milner and Me](ch07.md)
   * [What's Your Type?](ch07.md#whats-your-type)
   * [Tales from the Cryptic](ch07.md#tales-from-the-cryptic)
   * [Narrowing the Possibility](ch07.md#narrowing-the-possibility)
@@ -122,6 +122,7 @@
   * [match](appendix_c.md#match)
   * [prop](appendix_c.md#prop)
   * [reduce](appendix_c.md#reduce)
+  * [replace](appendix_c.md#replace)
   * [safeHead](appendix_c.md#safehead)
   * [safeLast](appendix_c.md#safelast)
   * [safeProp](appendix_c.md#safeprop)
@@ -130,6 +131,7 @@
   * [split](appendix_c.md#split)
   * [take](appendix_c.md#take)
   * [toLowerCase](appendix_c.md#tolowercase)
+  * [toString](appendix_c.md#tostring)
   * [toUpperCase](appendix_c.md#touppercase)
   * [traverse](appendix_c.md#traverse)
   * [unsafePerformIO](appendix_c.md#unsafeperformio)