Merge pull request #135 from Aws0mee/patch-1

Update using-prometheus-in-your-lua-application.md

Author: levno-710

doc/advanced/using-prometheus-in-your-lua-application.md

@@ -1,6 +1,6 @@
 # Using Prometheus in your Lua Application
 
-Prometheus can also be used as a library for your custom Lua Applications instead of using it's cli tool. 
+Prometheus can also be used as a library for your custom Lua Applications instead of using its cli tool. 
 
 In order to do that you'll first need to clone the github repo: