Minor README improvements; fix outdated URLs
Change-Id: Ia57f83892471ad85a2301ba4c8ab3df144581000
diff --git a/AUTHORS.md b/AUTHORS.md
index 5754f10..f25a767 100644
--- a/AUTHORS.md
+++ b/AUTHORS.md
@@ -2,7 +2,7 @@
The following lists maintainers, primary developers, and all much-appreciated contributors to ndn-tools in alphabetical order.
The specific contributions of individual authors can be obtained from the git history of the [official ndn-tools repository](https://github.com/named-data/ndn-tools).
-If you would like to become a contributor to the official repository, please follow the recommendations in <https://github.com/named-data/.github/blob/master/CONTRIBUTING.md>.
+If you would like to become a contributor to the official repository, please follow the recommendations in <https://github.com/named-data/.github/blob/main/CONTRIBUTING.md>.
* Jerald Paul Abraham <https://cs.arizona.edu/~jeraldabraham>
* ***(Maintainer)*** Alexander Afanasyev <https://users.cs.fiu.edu/~afanasyev>