Provide usage instruction in the readme

Author: fiodarsazanavets

README.md

@@ -1,2 +1,43 @@
 # NetCoreAudio
-Allows playback of audio files on .NET Core with minimal dependencies
+The library allows playback of audio files on .NET Core on any operating system with minimal dependencies
+
+# Usage
+
+The library exposes Player class, which detects the OS the library is running on and abstracts away any OS-specific audio playback implementations.
+
+## Properties
+
+### bool Plaing
+
+Indicates that the audio is currently playing.
+
+### bool Paused
+
+Indicates that the audio playback is currently paused.
+
+## Methods
+
+### Play(string fileName)
+
+Will stop any current playback and will start playing the specified audio file. The fileName parameter can be an absolute path or a path relative to the directory where the library is located. Sets Playing flag to true. Sets Paused flag to false.
+
+### Pause()
+
+Pauses any ongong playback. Sets Paused flag to true. Doesn't modify Playing flag.
+
+### Resume()
+
+Resumes any paused playback. Sets Paused flag to false. Doesn't modify Playing flag.
+
+### Stop()
+
+Stops any current playback and clears the buffer. Sets Playing and Paused flags to false.
+
+Stopped playback cannot be resumed. If the same file needs to be played again, it can only be played from the beginning.
+
+## Events
+
+### EventHandler PlaybackFinished
+
+Internally, sets Playing flag to false. Additional handlers can be attached to it to handle any custom logic.
+