[emacs] assimilate lean-mode and dependencies

[~bandali/configs] / lib / async

diff --git a/lib/async b/lib/async
new file mode 160000 (submodule)
index 0000000..04e1a2c
--- /dev/null
+++ b/lib/async
@@ -0,0 +1 @@
+Subproject commit 04e1a2c40bef305450389da540ffe7594964e430