Upgrade yarn lock file and package file (#1602)

Summary:
Hopefully this will help resolve some of the dependabot security alerts (in general we're unfortunately locked into some old dependencies due to docusaurus 1.x not receiving any more updates).

Tested by building site locally and checking it works as expected.

Pull Request resolved: #1602

Reviewed By: esantorella

Differential Revision: D42296577

Pulled By: Balandat

fbshipit-source-id: 5f5ea2f31f85cb0e971e27d163e210de3118da0c

Author: Balandat

website/package.json

@@ -12,6 +12,6 @@
     "docusaurus": "^1.14.7"
   },
   "dependencies": {
-    "bl": "^5.0.0"
+    "bl": "^6.0.0"
   }
 }