Majorly re-organize modules

- Split large modules into smaller parts (e.g. siren-text-manipulation)
- Organize modules into high level groups:
  - completion
  - core
  - editor
  - languages
  - linting
  - misc
  - navigation
  - projects
  - spelling
  - text-editing
  - version-control
  - windows
  - workspaces

modules/version-control/siren-git-timemachine.el

@@ -0,0 +1,15 @@
+;;; siren-git-timemachine.el --- jimeh's Emacs Siren: git-timemachine configuration.
+
+;;; Commentary:
+
+;; Basic configuration for git-timemachine.
+
+;;; Code:
+
+(use-package git-timemachine
+  :defer t
+  :init
+  (defalias 'gt 'git-timemachine))
+
+(provide 'siren-git-timemachine)
+;;; siren-git-timemachine.el ends here