README: Add link to BuildStream website

Also, buildstream -> BuildStream , for public-facing document.
diff --git a/README.rst b/README.rst
index a8f751c..eb0e275 100644
--- a/README.rst
+++ b/README.rst
@@ -1,10 +1,10 @@
 BuildStream Plugins
 ===================
-A collection of plugins for the BuildStream project.
+A collection of plugins for the `BuildStream <https://buildstream.build>`_ project.
 
 
 How to use plugins
 ------------------
-Plugins must be declared by your buildstream project.conf for use in your
-project. For instructions on how to load plugins in your buildstream project,
+Plugins must be declared by your BuildStream project.conf for use in your
+project. For instructions on how to load plugins in your BuildStream project,
 please consult the `plugin loading documentation <https://docs.buildstream.build/master/format_project.html#loading-plugins>`_