chore: fix comment

Signed-off-by: hanghuge <[email protected]>

src/templates/assets/javascripts/integrations/instant/index.ts

@@ -378,7 +378,7 @@ export function setupInstantNavigation(
 
  // Handle instant navigation events that are triggered by the user clicking
  // on an anchor link with the same hash fragment as the current one in the
- // URL. Is is essential that we only intercept those from instant navigation
+ // URL. It is essential that we only intercept those from instant navigation
  // events and not from history change events, or we'll end up in and endless
  // loop. The top-level history entry must be removed, as it will be replaced
  // with a new one, which would otherwise lead to a duplicate entry.