Adjusts the design of documentation as mentioned in the issue.

[ayushshukla1807]

Solves #514
Made these following changes:
Change the name "Pretix" to "eventyay" everywhere - DONE
Welcome to "Welcome to the documentation of the eventyay tickets component!"
Use eventyay logo and color as in Django
Change "Copyright Notice" to "© 2025 Apache 2.0 License by contributors" and reduce font size of Copyright notice
Change blog to https://blog.eventyay.com/
Add eventyay favicon
Github https://github.com/fossasia/eventyay-tickets/
Change let us know link https://github.com/fossasia/eventyay-tickets/issues/new

[hongquan]

Hi @ayushshukla1807
Are you about to create a PR? I'm confused with this issue. Its description sounds like a PR description.