Simplify Updates for Already Cached Repos & Add Autocomplete

[emanuelef]

I'd like to propose simplifying the update mechanism for repositories that are already cached. Instead of re-fetching the entire star history, we could retrieve only the new stars for the last few uncached days. This would benefit users who frequently return just to see the most recent star counts and speed up the update process.

Additionally, it would be helpful to add the last total number of stars, which is retrieved quickly, to the cumulative graph for better clarity.

Another improvement would be to implement autocomplete for repositories that are already cached, making it easier and faster for users to revisit their favorite repos.

What do you think about these ideas? Would love to hear your feedback!

[emanuelef]

Implemented in https://github.com/emanuelef/daily-stars-explorer/releases/tag/v0.0.6