build: switch source archive to xz compression
And a few minor README improvements
Change-Id: I667860f46b19d1ec885fd81910a116581007ac8f
diff --git a/docs/index.rst b/docs/index.rst
index 3af74fe..70f99fe 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -51,7 +51,7 @@
For developers
^^^^^^^^^^^^^^
-- `NDN Software Contributor's Guide <https://github.com/named-data/.github/blob/master/CONTRIBUTING.md>`__
+- `NDN Software Contributor's Guide <https://github.com/named-data/.github/blob/main/CONTRIBUTING.md>`__
(guide for newcomers to the NDN community of software)
- :doc:`specs`