Improve theme validation

themes/alphare

@@ -1,7 +1,8 @@
 # vim: filetype=yaml
 ---
 meta:
-  description: A beige theme by Alphare
+  author: Alphare
+  description: A beige theme
 colors:
   black: '#000000'
   oldlace: '#FDF6E3'

themes/archlinux

@@ -2,7 +2,9 @@
 # TODO: use color aliases to make the theme more readable
 ---
 meta:
-  description: 'Archlinux theme by okraits <http://okraits.de>'
+  author: okraits
+  url: http://okraits.de
+  description: 'Archlinux theme'
 window_colors:
   focused:
     border:           '#0088CC'

themes/base16-tomorrow

@@ -19,7 +19,9 @@ colors:
     base0F:              '#a3685a'
 
 meta:
-    description:         'Base16 Tomorrow, by Chris Kempson (http://chriskempson.com)'
+    author: Chris Kempson
+    url: http://chriskempson.com
+    description:         'Base16 Tomorrow'
 window_colors:
     focused:
         border:          'base0D'

themes/debian

@@ -2,7 +2,8 @@
 # TODO: use color aliases to make the theme more readable
 ---
 meta:
-  description: 'Debian theme by lasers'
+  author: lasers
+  description: 'Debian theme'
 window_colors:
   focused:
     border:           '#d70a53'

themes/deep-purple

@@ -1,7 +1,9 @@
 # vim: filetype=yaml
 ---
 meta:
-  description: 'Inspired by the Purple and Default themes. By jcpst <http://jcpst.com>'
+  author: jcpst
+  url: http://jcpst.com
+  description: 'Inspired by the Purple and Default themes.'
 bar_colors:
   separator: dimgrey
   background: black