Rename README file with MD extension to make GitHub happy

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+# LibRealmInfo
+
+World of Warcraft library for obtaining information about realms.
+
+
+## Download
+
+* [Curse](http://www.curse.com/addons/wow/librealminfo)
+* [WoWInterface](http://www.wowinterface.com/downloads/info)
+
+
+## Bugs & Requests
+
+* [GitHub](https://github.com/phanx/wow-librealminfo)
+
+
+## Usage
+
+	name, type, language, region = LibStub("LibRealmInfo"):GetRealmInfo(realmID)
+
+### Arguments
+
+1. `realmID` - number: the ID for the realm to query
+
+### Returns
+
+1. `name` - string: the name of the realm
+2. `type` - string: one of "PVE", "PVP", "RP" or "RPPVP"
+3. `language` - string: the official language of the realm, corresponds with GetLocale() values
+4. `region` - string: one of "US" or "EU" (other regions not yet supported)
+5. `subregion` - string/nil: an additional descriptor if other than what's indicated by the language and region, currently only "Oceanic" for US/Oceanic realms
+
+### Notes
+
+Realm IDs can be obtained on current 5.x live servers through Battle.net using [BNGetToonInfo](http://wowpedia.org/API_BNGetToonInfo):
+
+	_, _, _, _, realmID = BNGetToonInfo(presenceID or toonID)
+
+or [BNGetFriendToonInfo](http://wowpedia.org/API_BNGetToonInfo):
+
+	_, _, _, _, realmID = BNGetFriendToonInfo(friendIndex, toonIndex)
+
+The player's own presenceID can be obtained using BNGetInfo:
+
+	presenceID = BNGetInfo()
+
+In WoW 6.x (Warlords of Draenor) realm IDs can be obtained directly from GUIDs:
+
+	_, realmID = strsplit(":", UnitGUID("player"))
+
+Note that in 6.x the GUID format will change depending on the unit type; the above example will only work for player units. See here for more information.
+
+
+## Author & Credits
+
+Written by [Phanx](mailto:addons@phanx.net) widh data collected by
+[Vlad](http://www.wowinterface.com/forums/showthread.php?p=294425#post294425)
+and [Semlar](http://www.wowinterface.com/forums/showthread.php?p=294432#post294432).
+
+
+## License
+
+This is free and unencumbered software released into the public domain.
+
+See the accompanying LICENSE file for more details.
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diff --git a/README.txt b/README.txt
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-# LibRealmInfo
-
-World of Warcraft library for obtaining information about realms.
-
-
-## Download:
-
-* [Curse](http://www.curse.com/addons/wow/librealminfo)
-* [WoWInterface](http://www.wowinterface.com/downloads/info)
-
-
-## Bugs & Requests:
-
-* [GitHub](https://github.com/phanx/wow-librealminfo)
-
-
-## Author & Credits:
-
-Written by [Phanx](mailto:addons@phanx.net) widh data collected by
-[Vlad](http://www.wowinterface.com/forums/showthread.php?p=294425#post294425)
-and [Semlar](http://www.wowinterface.com/forums/showthread.php?p=294432#post294432).
-
-
-## License:
-
-This is free and unencumbered software released into the public domain.
-
-See the accompanying LICENSE file for more details.
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