Update README.md

Author: devxoul

README.md

@@ -7,15 +7,17 @@
 
 A simple local reverse proxy server for HLS segment cache.
 
-## Concept
+## How it works
 
-1. **User** sets a reverse proxy url instead of original url.
+![HLSCachingReverseProxyServer Concept](https://user-images.githubusercontent.com/931655/69081879-45206a80-0a82-11ea-8fca-3c09f3b1ebb1.png)
+
+1. **User** sets a reverse proxy url to the `AVPlayer` instead of the origin url.
     ```diff
     - https://example.com/vod.m3u8
     + http://127.0.0.1:8080/vod.m3u8?__hls_origin_url=https://example.com/vod.m3u8
     ```
-2. **AVAsset** requests a playlist(`.m3u8`) to the local reverse proxy server.
-3. **Reverse proxy server** fetches the original playlist and replaces all URIs to point the local reverse proxy server.
+2. **AVPlayer** requests a playlist(`.m3u8`) to the local reverse proxy server.
+3. **Reverse proxy server** fetches the origin playlist and replaces all URIs to point the localhost.
     ```diff
       #EXTM3U
       #EXTINF:12.000,
@@ -28,8 +30,8 @@ A simple local reverse proxy server for HLS segment cache.
     - vod_00003.ts
     + http://127.0.0.1:8080/vod.m3u8?__hls_origin_url=https://example.com/vod_00003.ts
     ```
-4. **AVAsset** requests segments(`.ts`) to the local server.
-5. **Reverse proxy server** fetches the original segment and caches. Next time the server will return the cached data for the same segment.
+4. **AVPlayer** requests segments(`.ts`) to the local reverse proxy server.
+5. **Reverse proxy server** fetches the origin segment and caches it. Next time the server will return the cached data for the same segment.
 
 ## Usage
 
@@ -38,8 +40,8 @@ let server = HLSCachingReverseProxyServer()
 server.start(port: 8080)
 
 let playlistURL = URL(string: "http://devstreaming.apple.com/videos/wwdc/2016/102w0bsn0ge83qfv7za/102/0640/0640.m3u8")!
-let url = server.reverseProxyURL(from: playlistURL)!
-let playerItem = AVPlayerItem(url: url)
+let reverseProxyURL = server.reverseProxyURL(from: playlistURL)!
+let playerItem = AVPlayerItem(url: reverseProxyURL)
 self.player.replaceCurrentItem(with: playerItem)
 ```
 
@@ -50,7 +52,7 @@ self.player.replaceCurrentItem(with: playerItem)
 
 ## Installation
 
-**Podfile**
+Use CocoaPods with **Podfile**:
 
 ```ruby
 pod 'HLSCachingReverseProxyServer'