~refactor theme module to have it's own namespace

oreodave/theme is the dedicated function/state namespace for theme
management. It's just cleaner and nicer.

doom.d/modules/config.org

@@ -354,7 +354,7 @@ each of the unit tests ran."
  :desc   "Open school dir"    "s"     #'oreodave/goto-school ; I like my schooling
  :desc   "Open weather"       "w"     #'oreodave/weather ; Nah I don't like the weather
  :desc   "Open notes"         "n"     #'(lambda () (interactive) (dired org-directory))
- :desc   "Change theme"       "t"     #'oreodave/set-new-theme ; From my own collection
+ :desc   "Change theme"       "t"     #'oreodave/theme/set-new-theme ; From my own collection
  (:after pdf-view
    :desc "Goto page on pdf"   "p"     #'pdf-view-goto-page)
  :desc   "Reload emacs"       "r"     #'oreodave/reload) ; Reload is necessary

doom.d/modules/personal.org

@@ -21,11 +21,11 @@ doom private directory.
 Open a Dired session to the books directory in the org-directory.
 * Change theme
 #+BEGIN_SRC elisp
-(setq oreodave/theme-list '(doom-solarized-dark doom-gruvbox doom-city-lights
+(setq oreodave/themes/theme-list '(doom-solarized-dark doom-gruvbox doom-city-lights
                                                 doom-outrun-electric doom-vibrant doom-molokai
                                                 doom-solarized-light doom-acario-light))
 
-(defun oreodave/set-new-theme ()
+(defun oreodave/themes/set-new-theme ()
   "Set the theme from my own selection, mutate as you see fit"
   (interactive)
   (ivy-read "Select theme: "