feat: improve update button visibility (#3115)

* feat: give update button primary focus when applicable

resolves #3024

* added update tooltip

* cleanup

* prettier

* PR feedback

site/src/util/createDayString.ts

@@ -0,0 +1,9 @@
+import dayjs from "dayjs"
+
+/**
+ * Returns a human-readable string describing the passing of time
+ * Broken into its own module for testing purposes
+ */
+export function createDayString(time: string): string {
+  return dayjs().to(dayjs(time))
+}