Update BattleMod with filter xml file information

[ayechonk]

Just a suggestion and I apologize if it comes across as nit picky. I was trying to customize the BattleMod addon last night and had no clue I needed to create and alter filter files until I went to the GitHub page. I feel like that information should be represented on http://docs.windower.net/addons/battlemod/ I feel like github is for developers not the average user. Anyways just a thought. Thank you for all your hard work!

[zetaepyon]

Just as an FYI, since the docs are updated manually, the GitHub link for the addon is always the ultimate source of truth.

I can probably take care of this this weekend.