For those of you who don't know, it is possible to run Brawl Mods in Steam for use with it's Big Picture Mode which can work with the Steam Link. No longer will you have to be constrained to your Wii/Wii U to play the great mods available for Brawl, (Project M, Brawl Minus, or even BrawlEx Packs such as Kitsu's BrawlEx pack or Tyshy's Super Smash Sisters games.) Or your own personal brawl mod pack in the same constants the game had on the original Wii. And no longer will you have to be stuck at your computer while you could be playing it on the big screen. (Unless you're like me, and have your PC hooked up to your TV.)
(If you want to know how to run Brawl mods in Dolphin though, check out KingJigglypuff's tutorial.
http://forums.kc-mm.com/index.php?topic=75863.0)
After getting your mod set up to run from Dolphin, open up Steam, go to your library, click where it says, "Games" then click, "Add a Non-Steam game to my library" Click browse and search your computer for where you put the Dolphin.exe program at. Ex:"C:\Users\Ausu\Documents\My Games\Ishiiruka Dolphin\" for me. Then click, "Add selected programs. Now you'll have the Dolphin emulator in your Steam Library, but it won't launch any game or mod right away. You then have to right click dolphin and go down to properties. First thing to do there is to rename Dolphin in steam to your mod's name, Ex: "Super Smash Bros. Project M". Then in the target box, go to the end of the filepath for your Dolphin emulator, And add -e right at the end of the quote, then press the Spacebar, go to where your Gecko OS elf file is, Hold Shift+Right Click the file, and select "Copy as path" Then paste that into the target box, then /b at the end. For an example I've done on my computer,
"C:\Users\User\Documents\ My Games\Ishiiruka Dolphin\Dolphin.exe"-e "C:\Users\User\Documents\My Games\Wii\Gecko OS.elf" /b" What that'll do is force Dolphin to load Gecko straight up without you having to open the file up manually.
Now go to your Steam Link, go to your library, and your game mod should be there in your list of games to stream.
(Though if you don't have Steam Link, or you don't want to stream the game in general, you can still launch the game through normal Steam or Big Picture Mode.)
One more thing that you probably notice about your mod, it lacks a Steam Banner. You have to manually add it yourself.
To do that, go to your view mode, and change it to Grid. Now you should see the Steam Banners for all of your other games except for your mod which is just trying to use Dolphin's default icon. Then all you have to do is get a Steam Banner for it. You can visit
http://steambanners.booru.org/ to find a banner for the mod your looking for, or make your own. Just know that it needs to be atleast 460x215 in dimensions. Right click your mod and select, "Set custom image" Click browse, then search for your Banner, double click it, then click, "Set Image" And ta-da. Your mod now has a steam banner for it. Do note, you can't delete the banner after setting it as the default banner for your mod.
Hope this tutorial helps you out.