Added release note snippet for prebuilt shared libs.

docs/markdown/snippets/prebuilt.md

@@ -0,0 +1,15 @@
+# Better support for prebuilt shared libraries
+
+Meson has had support for prebuilt object files and static libraries.
+This release adds feature parity to shared libraries. This means
+that e.g. shipping prebuilt libraries as subprojects now can
+be as simple as writing a definition file that looks like this.
+
+    project('myprebuiltlibrary', 'c')
+    
+    cc = meson.get_compiler('c')
+    prebuilt = cc.find_library('mylib', dirs : meson.current_source_dir())
+    mydep = declare_dependency(include_directories : include_directories('.'),
+                               dependencies : prebuilt)
+
+Then you can use the dependency object in the same way as any other.