Update README for Hacktoberfest changes for 2025.

[ClJarvis]

Digital Ocean has increased the number of pull requests need to complete HacktoberFest. For 2025 they require 6 accepted PRs to complete the challenge. The README needs to be update to reflect that. It still has the old number of 4 PRs.

https://hacktoberfest.com/

[danieltayal07]

i have submitted a pr for the same