Typo in readme, add Termcolor to CREDITS.

CREDITS

@@ -34,3 +34,8 @@ epubgrep makes direct use of the following libraries and programs:
     From: fmt community
           https://github.com/fmtlib/fmt
     License: MIT
+
+  Termcolor
+    From: Ihor Kalnytskyi
+          https://termcolor.readthedocs.io/
+    License: BSD-3-Clause

README.adoc

@@ -14,7 +14,7 @@
 :uri-libarchive: https://www.libarchive.org/
 :uri-fmt: https://github.com/fmtlib/fmt
 :uri-asciidoc: http://asciidoc.org/
-uri-termcolor: https://termcolor.readthedocs.io/
+:uri-termcolor: https://termcolor.readthedocs.io/
 
 *{project}* is a search tool for EPUB e-books.