[Init] Some initial comments

init.el

@@ -2,6 +2,18 @@
 
 ;;; Commentary:
 
+;; This is the main entry point for Emacs to load this configuration.  The
+;; structure is roughly as follows:
+;; * first comes some preliminary setup, mostly setting up `package’;
+;; * the main activation of the configuration is done in the function
+;;   `db/run-init’, which is installed in `after-init-hook’; it is thus run
+;;   after init.el has been read
+;; * then comes setting up all the packages that can be used by this
+;;   configuration; most of these packages are not loaded however, and only
+;;   configuration hooks are installed (using `use-package’); this way a user
+;;   can choose in `db/run-init’ which configruation to activate without
+;;   changing much of the rest of the file.
+
 ;;; Code: