Really fix the readme formatting now

The previous change attempted to make sure we display the
project links in separate lines. Sphinx started complaining about
this though:

    /Users/user/projects/netaddr/docs/source/reference/cli.rst:122: WARNING: Line block ends without a blank line.

README.rst

@@ -34,7 +34,9 @@ Layer 2 addresses
 -  generating derived IPv6 addresses
 
 | Documentation: https://netaddr.readthedocs.io/en/latest/
+
 | Source code repository: https://github.com/netaddr/netaddr/
+
 PyPI page: https://pypi.org/project/netaddr/
 
 Share and enjoy!