Update README.md

Author: NurikHISPlayer

README.md

@@ -21,7 +21,7 @@ HISPlayer is the most advanced Unity video streaming player for iOS, supporting
 
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-## [REQUEST FREE DEMO HERE!](https://hisplayer.com/demo-unity-player-sdk-github/?utm_source=github&utm_medium=referral&utm_campaign=unitygithub&utm_content=20200211--unitydemocontact)
+## [REQUEST A DEMO HERE!](https://hisplayer.com/demo-unity-player-sdk-github/?utm_source=github&utm_medium=referral&utm_campaign=unitygithub&utm_content=20200211--unitydemocontact)
 
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