docs: add docsify and move documentation to docs

[EngrKhizarIqbal]

Summary

PR follow up from the discussion we had in #22

Details

• Added docsify to the project.
• Split readme.md into multiple files under the docs folder.

[balazsbotond]

Never mind, I've resolved the conflicts.

I've also checked the web site and it looks great - thank you! I will publish it soon on https://urlcat.dev

[balazsbotond]

@all-contributors please add @EngrKhizarIqbal for infrastructure

[allcontributors[bot]]

@balazsbotond

I've put up a pull request to add @EngrKhizarIqbal! :tada:

[balazsbotond]

@EngrKhizarIqbal the new site is live at https://urlcat.dev - and in my opinion, it looks awesome! Thanks again!