Created Beatmap class terminology (markdown)

Beatmap-class-terminology.md

@@ -0,0 +1,31 @@
+## Models
+
+### Beatmap
+
+### BeatmapInfo
+
+### BeatmapSetInfo
+
+### WorkingBetamap
+
+## Gameplay
+
+The easiest way to obtain a final playable beatmap is to first obtain a `WorkingBeatmap` and then call `GetPlayableBeatmap()`. It will run through the following steps:
+
+### BeatmapConverter
+
+Converts a beatmap from one ruleset to another. Note that this should be run even if there is no conversion (using the actual ruleset of the beatmap). It will generally be a no-op.
+
+### BeatmapProcessor
+
+Takes a post-converted beatmap and applies any final touches to make the beatmap ready for gameplay purposes.
+
+## Importing and processing
+
+### BeatmapManager
+
+### BeatmapUpdater
+
+### BeatmapOnlineLookupQueue
+
+### BackgroundBeatmapProcessor