Add configuration option to conceal links and enabling cleaner folds

plugin/org.vim

@@ -6,6 +6,11 @@
 " Website:      https://github.com/axvr/org.vim
 " Last Change:  2019-09-22
 
+" Fallback chain for options. Buffer local --> Global --> default.
+function org#option(name, default)
+    return get(b:, a:name, get(g:, a:name, a:default))
+endfunction
+
 if !exists('g:org_state_keywords')
     let g:org_state_keywords = ['TODO', 'NEXT', 'DONE']
 endif