script: contribute "light" theme overrides

Add script-theme.{c,h} with the script plugin contribution to the
built-in "light" theme: 24 entries on script.color.* (status_* and
text_*) tuned for a light-background terminal.

Same 2D-array pattern as the other plugin contributions.

Default option values are NOT changed.

src/plugins/script/script.c

@@ -37,6 +37,7 @@
 #include "script-info.h"
 #include "script-mouse.h"
 #include "script-repo.h"
+#include "script-theme.h"
 
 
 WEECHAT_PLUGIN_NAME(SCRIPT_PLUGIN_NAME);
@@ -352,6 +353,8 @@ weechat_plugin_init (struct t_weechat_plugin *plugin, int argc, char *argv[])
 
     script_config_read ();
 
+    script_theme_init ();
+
     weechat_mkdir_home ("${weechat_cache_dir}/" SCRIPT_PLUGIN_NAME, 0755);
 
     script_command_init ();