You can upload your files on Pastebin or similar services that save the files for longer than a day or so.
These files will be put at the root of the server's data folder.
They must also be named bf_mapname.json, so for example a file for Dust 2 would be bf_de_dust2.json

I'll go first:
gm_construct[pastebin.com]
gm_fork[pastebin.com]
gm_northwest_airfield[pastebin.com]
rp_deadcity[pastebin.com]
bf_speedball[pastebin.com]
gm_brokenvillage[pastebin.com]

WARNING! Some of these maps are not a good example of maps that should be used for this:

gm_construct - Players spawn too close together, tight spaces, large open field
gm_northwest_airfield - Players spawn too close together, large runway
rp_deadcity - Players spawn too close together