Update Release_Notes_4.0 alpha3

Release_Notes_4.0-alpha3.md

@@ -15,6 +15,23 @@ Apprmor 4.0 is a bridge release between older AppArmor 3.x policy and the newer
 * AppArmor 4.0 contains all bug fixes and policy updates from apparmor 3.1
 * Some new features will not be fully supported in some utilities. In these cases it was decided that releasing a new feature earlier had more benefit than delaying it for full utility support. Please see the feature support matrix.
 
+# Obtaining this release
+There are two ways to obtain this release either through gitlab or a tarball in launchpad. 
+
+**Important note:** the gitlab release tarballs differ from the launchpad release tarballs. The launchpad release tarball has a couple processing steps already performed:
+
+* libapparmor `autogen.sh` is already done, meaning distros only need to use ./configure in their build setup
+* the docs for everything but libapparmor have already been built
+
+### gitlab
+- https://gitlab.com/apparmor/apparmor/-/releases/v3.1.2
+
+### Launchpad
+  -   <https://launchpad.net/apparmor/3.1/3.1.2/+download/apparmor-3.1.2.tar.gz>
+  -   sha256sum: 7cbd0b2f6393abf57acaf25dc2b32b2ae197c0b5b0d661e14be46127df93a5eb
+  -   signature: <https://launchpad.net/apparmor/3.1/3.1.2/+download/apparmor-3.1.2.tar.gz.asc>
+  -   signature sha256sum: 7cd2a44a695caf906f3328d1b654c65a454737f6
+
 # Highlighted new features in alpha 3
 
 ## New Profile Flag