[emacs] assimilate slack and deps, clear up .gitignore, add secrets

[~bandali/configs] / lib / slack

diff --git a/lib/slack b/lib/slack
new file mode 160000 (submodule)
index 0000000..792604d
--- /dev/null
+++ b/lib/slack
@@ -0,0 +1 @@
+Subproject commit 792604db287de2a986177d90f086f5d51aa5b403