Add Caching
We don't want to hit the lobste.rs servers harder than necessary, so we should implement some basic form of caching such that...
- If the current cache is 1hr+ for the home page (hot), don't refresh unless manually refreshed by the user.
- If the current cache is 30min for the home page (new), don't refresh unless manually refreshed by the user.
- If the current cache for the comments page is more than 1hr old, don't refresh unless manually refreshed by the user.
- Display the current age of the cache for that specific item in the bar at the top. (Last Updated: x hr ago)
- Delete old caches when possible to not create bloat.