docs: adjust verb tense in performant blurb (#1292)

Author: sheriffderek

docs/index.md

@@ -23,7 +23,7 @@ features:
   - title: Idiomatic
     details: Use composables that align with the declarative approach of Vue. Everything that can be automatically handled by VueFire is. Nested Collections, Document References, and more, are all handled for you.
   - title: Performant
-    details: VueFire only handles the binding for you so your state is always up to date with the server. You still be able to use Firebase JS SDK to its full potential!
+    details: VueFire only handles the binding for you so your state is always up to date with the server. You'll still be able to use the Firebase JS SDK to its full potential!
   - title: Flexible
     details: Use Firebase Database, Firestore, Authentication, etc. VueFire exposes tree-shakable APIs that are built on top of the Firebase modular JS SDK.