Update link to Port a Google Chrome Extension

Changed link target to https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/Porting_a_Google_Chrome_extension.

_includes/home/build.md

@@ -107,7 +107,7 @@ Already have an extension that works in Chrome? Bring your app to Firefox in a f
 
 Top Resources  
 [Differences between Chrome and Firefox](https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/Chrome_incompatibilities)
-[Port a Google Chrome extension](https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/Porting)
+[Port a Google Chrome extension](https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/Porting_a_Google_Chrome_extension)
 
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