Suggestion - ISteamFriends::GetPersonaName

[GuglioIsStupid]

Would be a really neat addition to add this, doc link: https://partner.steamgames.com/doc/api/ISteamFriends#GetPersonaName
Returns the current steam users username

(sorry if this is the wrong place to put this)

[yancouto]

I'm not actively adding stuff, but feel free to submit a PR, this should be similar to the GetFriendPersonaName we already have.

Also, have you tried using luasteam.friends.getFriendPersonaName(luasteam.user.getSteamID())? The documentation doesn't guarantee it, but I think it might work, I'm pretty sure I did this in my game.

[keharriso]

See #41