Add module for slim-mode, and leave it disabled for now

After experimenting with slim for a project, I decided against
it. However I'd created a module for it for my emacs config here, so
might as well keep it around for next time I come across slim.

core/siren-modules.el

@@ -101,6 +101,7 @@
 (require 'siren-thrift)
 (require 'siren-web-mode)
 (require 'siren-yaml)
+;; (require 'siren-slim)
 
 (provide 'siren-modules)
 ;;; siren-modules.el ends here

modules/siren-slim.el

@@ -0,0 +1,21 @@
+;;; siren-slim.el --- jimeh's Emacs Siren: slim-mode configuration.
+
+;;; Commentary:
+
+;; Basic configuration for slim-mode.
+
+;;; Code:
+
+(use-package slim-mode
+  :mode "\\.slim\\'"
+
+  :config
+  (defun siren-slim-mode-defaults ()
+    (siren-prog-mode-defaults)
+    (highlight-indentation-current-column-mode))
+
+  (setq siren-slim-mode-hook 'siren-slim-mode-defaults)
+  (add-hook 'slim-mode-hook (lambda () (run-hooks 'siren-slim-mode-hook))))
+
+(provide 'siren-slim)
+;;; siren-slim.el ends here