add to readme links to integration libraries

[vgavro]

Is your feature request related to a problem? Please describe.
It may be convenient for users to improve readme with links to projects that integrates curl_cffi to other libraries

Describe the solution you'd like
Add to readme links to https://github.com/vgavro/httpx-curl-cffi and https://pypi.org/project/httpie-curl-cffi/

Describe alternatives you've considered

Additional context

[lexiforest]

I'll add a section later.