docs: fix up grammar typos (#678)

These are small grammar fixes for the index page

Author: codr

docs/src/routes/index.mdx

@@ -36,7 +36,7 @@ Partytown's philosophy is that the main thread should be dedicated to your code,
 
 ## Negative Impacts from Third-Party Scripts
 
-Below is a summary of potential issues after add third-party scripts, referenced from [Loading Third-Party JavaScript](https://developers.google.com/web/fundamentals/performance/optimizing-content-efficiency/loading-third-party-javascript):
+Below is a summary of potential issues after adding third-party scripts, referenced from [Loading Third-Party JavaScript](https://developers.google.com/web/fundamentals/performance/optimizing-content-efficiency/loading-third-party-javascript):
 
 - Firing too many network requests to multiple servers. The more requests a site has to make, the longer it can take to load.
 - Sending too much JavaScript which keeps the main thread busy. Too much JavaScript can block DOM construction, delaying how quickly pages can render.
@@ -64,7 +64,7 @@ Below are just a few examples of third-party scripts that might be a good candid
 
 ## "Ready to Party" Plugins / Libraries
 
-We try and keep a list of all the plugins and libraries that we know of that works out-of-the-box in Partytown, but we would love your help as plugin & library authors and contributors to keep this list growing.
+We try and keep a list of all the plugins and libraries that we know of that work out-of-the-box in Partytown, but we would love your help as plugin & library authors and contributors to keep this list growing.
 
 We have [some documentation](https://github.com/BuilderIO/partytown/blob/main/CONTRIBUTING.md#plugin-authors--developers) on how you could create and check-in an integration test that shows how your library / plugin works on Partytown. And if it works, then we would love to have the configuration needed (if any) on our [Common Services page](/common-services)