Display the structure of the credentials file
Examples
show_example_file()
#> user_name password host_name
#> 1 admin district https://play.im.dhis2.org/dev
#> 2 rfamro mysql-rfam-public.ebi.ac.uk
#> 3 kmane 9A81268476645C4E5F03428B8AC3AA7B https://bbmc.ouhsc.edu/redcap/api/
#> project_id comment dbms port
#> 1 DHIS2_DEMO this is a test DHIS2 server DHIS2 NA
#> 2 Rfam this is a test MySQL server MySQL 4497
#> 3 SD_DATA testing access to REDCap project REDCap NA