Update README.md

fix the grammars

Author: gafferongames

README.md

@@ -1,6 +1,6 @@
 # Browser extensions for netcode.io
 
-This repository enables the use of [netcode.io](https://github.com/networkprotocol/netcode.io) via browser extensions, prior to it's adoption in browsers.
+This repository enables the use of [netcode.io](https://github.com/networkprotocol/netcode.io) via browser extensions, prior to its adoption in browsers.
 
 **This is super experimental right now!**
 
@@ -113,4 +113,4 @@ The primary goals for this project currently are:
 - Getting the extension into the relevant extension web stores
 - Making the installation of the extension and native helper easy enough for players to install it upon prompting from HTML5 games
 
-All pull requests must be made available under an MIT license.
+All pull requests must be made available under an MIT license.