let's not use otl for random files in this wiki

it's slow

diff --git a/doc/todo/add_forward_age_sorting_option_to_inline.otl b/doc/todo/add_forward_age_sorting_option_to_inline.mdwn
similarity index 100%
rename from doc/todo/add_forward_age_sorting_option_to_inline.otl
rename to doc/todo/add_forward_age_sorting_option_to_inline.mdwn