Change ini name, add comment to ini file
Changes ini file name from a GraceDB event ID based name (eg. G298936.ini) to bilby_config.ini, this is to easily distinguish between ini files created using different PE codes for online PE. Other files such as the config_complete.ini and output json files will still have the GraceDB event ID in the name.
Adds comment to start of ini file which gives the GraceDB superevent ID the information was retrieved from. If superevent is not listed/available, superevent is given as 'None' in the comment.