If you have made the map then you must add all the files you exported into the folder you are putting up for a .zip download. The files you must put into the new folder are .fhm .fho .fhw .fhs files that are located in the exports folder after you have exported the map. You will know what they are named because it will tell you what files are named when being exported when you are exporting the map. Now, for the "Readme" file you must create instructions and any other stuff you want to add such as credits and copy rights. The instructions must be something like this:
"All .fho .fhm .fhw and .fhs files that are found in this folder belong in FeralHeart\Exports."
I suggest creating that it a word document or notepad once you have done that you need to save it into the folder you have but all the other files in. Finally, right click the folder that has all your map files and the readme then select "Send to >> Compressed.zipped folder" then upload it to mediafire or any other file sharing site. Hope this helped!