[CI] Add CI script, add export script

Drone script calls new `export.el' script written in Emacs Lisp to
export all org files to HTML files.

HTML files should then be uploaded to a remote server with SCP

export.el

@@ -0,0 +1,21 @@
+#!/usr/bin/emacs --script
+(require 'package)
+(add-to-list 'package-archives '("melpa" . "https://melpa.org/packages/") t)
+(package-initialize)
+(package-refresh-contents)
+(package-install 'htmlize)
+(package-install 's)
+(require 's)
+(setq org-confirm-babel-evaluate nil)
+(let* ((files (mapcar #'expand-file-name
+                      (file-expand-wildcards "org/config/*.org"))))
+  (mapc (lambda (file)
+          (message (format "==========\nExporting %S\n==========" file))
+          (with-current-buffer (find-file file)
+            (org-html-export-to-html)))
+        files))
+(let* ((files (mapcar #'expand-file-name
+                      (file-expand-wildcards "org/config/*.html~"))))
+  (mapc (lambda (file)
+          (delete-file file))
+        files))