Fix Typos and Bugs (#740)

Author: epodol

react/src/pages/Account/Checkouts.tsx

@@ -71,7 +71,7 @@ const CheckoutRow = ({ checkoutID }: { checkoutID: string }) => {
           disabled={
             (libraryDoc.checkoutGroups[userDoc.checkoutGroup].maxRenews ?? 0) -
               checkout.renewsUsed <=
-            0
+              0 || checkout.dueDate.toMillis() > Date.now()
           }
           onClick={() => {
             httpsCallable(

react/src/pages/CustomPage/About/DueDates.tsx

@@ -31,7 +31,7 @@ const DueDates = () => (
         </ul>
       </li>
       <li>
-        In the event that a book will due on an academic or national holiday or
+        In the event that a book is due on an academic or national holiday or
         break, the book will be due on{' '}
         <b className="font-weight-bold">the first day back</b>.
         <ul>

react/src/pages/CustomPage/About/Introduction.tsx

@@ -9,7 +9,7 @@ const Introduction = () => (
       students can come check out books for their enjoyment. This will also
       serve as a resource center for students to acquire more knowledge about
       their fields of study. The library will be designed in a way where
-      everyone will be be able to check out books for a reasonable time frame to
+      everyone will be able to check out books for a reasonable time frame to
       ensure that all students have equal access to our catalog! We hope to see
       you there!
     </p>