Update comments of building script (#800)

Author: suzuki

build

@@ -44,8 +44,8 @@ Versions:
   26                    Emacs 26 - emacs-plus@26 - previous release
   27                    Emacs 27 - emacs-plus@27 - previous release
   28                    Emacs 28 - emacs-plus@28 - previous release
-  29                    Emacs 29 - emacs-plus@29 - current release
-  30                    Emacs 30 - emacs-plus@30 - development (emacs-30)
+  29                    Emacs 29 - emacs-plus@29 - previous release
+  30                    Emacs 30 - emacs-plus@30 - current release
   31                    Emacs 31 - emacs-plus@31 - development (master)
 
 Consult each formula for the list of available options.