build: referencing codecov in changelog

CHANGELOG.md

@@ -4,9 +4,10 @@
 
 Version 1.7.0 includes support for the [CMake](https://cmake.org) build
 system. While the existing autotools environment will be supported for a time,
-this will be removed in a future release. This version also includes many
-changes to improve testing coverage across all interfaces, and make the
-interfaces across objects consistent.
+this will be removed in a future release.
+This version also includes many changes to improve
+[testing coverage](https://app.codecov.io/gh/jgaeddert/liquid-dsp/)
+across all interfaces, and make the interfaces across objects consistent.
 
   * build
     - migrated to the [CMake](https://cmake.org) build system, including
@@ -25,6 +26,7 @@ interfaces across objects consistent.
     - replaced warnings with internal error handling for many existing object
       methods
     - fixed SONAME not set in shared library (thanks again, @andreasbombe)
+    - migrated README from markdown to re-structured text
   * framing
     - added more description to method definitions such as qpacketmodem and
       qdetector