Update core-dotspacemacs.el default font size

0ffdb353f9 changed the default config template to use a point size instead of a pixel size.  Change the defvar declaration as well.

Commit modified by duianto:
Updated font size in doc/documentation.org

CHANGELOG.develop

@@ -484,7 +484,7 @@ Other:
   - Allow customizing default major mode for new empty buffers in ~SPC b N n~,
     see =dotspacemacs-new-empty-buffer-major-mode= (thanks to Juha Jeronen)
   - Changed =dotspacemacs-default-font= =:size= from =13= (pixel size) to =10.0=
-    (point size) (thanks to duianto)
+    (point size) (thanks to Aaron Zeng and duianto)
 - Fixed:
   - Avoid non-idempotent use of push in init code (thanks to Miciah Masters)
   - Moved Spacemacs startup progress bar to =core-progress-bar.el=, removed

core/core-dotspacemacs.el

@@ -226,7 +226,7 @@ emacs.")
 ;; emacs.")
 
 (defvar dotspacemacs-default-font '("Source Code Pro"
-                                    :size 13
+                                    :size 10.0
                                     :weight normal
                                     :width normal)
   "Default font, or prioritized list of fonts. This setting has no effect when

doc/DOCUMENTATION.org

@@ -1191,7 +1191,7 @@ To change the default font set the variable =dotspacemacs-default-font= in your
 
 #+BEGIN_SRC emacs-lisp
   (setq-default dotspacemacs-default-font '("Source Code Pro"
-                                            :size 13
+                                            :size 10.0
                                             :weight normal
                                             :width normal))
 #+END_SRC