refactor: move templates/ to static/

To better reflect what this directory is intended to store (i.e. not
just templates).

static/QUICKSTART_INTRO

@@ -0,0 +1,15 @@
+But before you doom yourself, here are some things you should know:
+
+1. Don't forget to run 'doom sync' and restart Emacs after modifying init.el or
+   packages.el in ~/.config/doom. This is never necessary for config.el.
+
+2. If something goes wrong, run `doom doctor` to diagnose common issues with
+   your environment, setup, and config.
+
+3. Use 'doom upgrade' to update Doom. Doing it any other way will require
+   additional steps (see 'doom help upgrade').
+
+4. Access Doom's documentation from within Emacs via 'SPC h d h' or 'C-h d h'
+   (or 'M-x doom/help').
+
+Have fun!