Order list of conferences, add HRI

I just added a list of conferences (https://www.cu-adcl.org/posts/conferences/) it would be nice to edit this file: https://github.com/CU-ADCL/CU-ADCL.github.io/blob/main/posts/conferences.md to order them in terms of submission month and add some missing ones (like HRI).

If someone knows enough javascript, we could even make it a sortable table!