Genre & category filters

[LiamGallagher737]

Add support for filtering by genre and category.

The steam API returns the following

"categories": [
    {
        "id": 1,
        "description": "Multi-player"
    },
    {
        "id": 20,
        "description": "MMO"
    },
    {
        "id": 49,
        "description": "PvP"
    },
    {
        "id": 36,
        "description": "Online PvP"
    },
    {
        "id": 18,
        "description": "Partial Controller Support"
    }
],
"genres": [
    {
        "id": "23",
        "description": "Indie"
    },
    {
        "id": "29",
        "description": "Massively Multiplayer"
    },
    {
        "id": "9",
        "description": "Racing"
    },
    {
        "id": "70",
        "description": "Early Access"
    }
],

[LiamGallagher737]

List of ID's and descriptions
files.catbox.moe/96bty7.json

[LiamGallagher737]

List of ID's and descriptions
files.catbox.moe/96bty7.json

This doesn't match up with the response in the issue.