Rename `+distribution` to `+distributions`

core/core-configuration-layer.el

@@ -900,7 +900,7 @@ path."
       (let* ((layer-name (if (listp layer) (car layer) layer))
              (layer-path (ht-get configuration-layer-paths layer-name)))
         (if (stringp layer-path)
-            (unless (string-match-p "+distribution" layer-path)
+            (unless (string-match-p "+distributions" layer-path)
               (configuration-layer/declare-layer layer))
           (spacemacs-buffer/warning "Unknown layer %s declared in dotfile."
                                     layer-name))))

core/core-dotspacemacs.el

@@ -50,7 +50,7 @@ exists. Otherwise, fallback to ~/.spacemacs")
 
 (defvar dotspacemacs-distribution 'spacemacs
   "Base distribution to use. This is a layer contained in the directory
-`+distribution'. For now available distributions are `spacemacs-base'
+`+distributions'. For now available distributions are `spacemacs-base'
 or `spacemacs'.")
 
 (defvar dotspacemacs-elpa-https t

doc/FAQ.org

@@ -123,7 +123,7 @@ experience.
 
 Set the distribution with =dotspacemacs-distribution= variable. The default is
 =spacemacs=. For more information as to what is included, check out the
-=packages.el= file in the respective folders in the =+distribution= folder of
+=packages.el= file in the respective folders in the =+distributions= folder of
 the =layers/= directory.
 
 ** Should I place my settings in =user-init= or =user-config=?