Add SteamDB spice

**What does your instant answer do?**
Searches games released on Steam and links to them.

**What is the data source for your instant answer? (Provide a link if possible)**
[SteamDB](http://steamdb.info)

**Why did you choose this data source?**
I am a developer of SteamDB.

**What are some example queries that trigger this instant answer?**
* steam team fortress
* steam left 4 dead
* dayz steam

**Which communities will this instant answer be especially useful for?**
Gamers.

![13 12 26 qgdw0](https://f.cloud.github.com/assets/613331/1811577/cdd984da-6e5a-11e3-99d7-54565a942df4.png)