chore: adds bg removal api example

[bhimrazy]

Before submitting

• Was this discussed/agreed via a Github issue? (no need for typos and docs improvements)
• Did you read the contributor guideline, Pull Request section?
• Did you make sure to update the docs?
• Did you write any new necessary tests?

What does this PR do?

Adds an example for deploying background removal API using LitServe to README

PR review

Anyone in the community is free to review the PR once the tests have passed.
If we didn't discuss your PR in GitHub issues there's a high chance it will not be merged.

Did you have fun?

Make sure you had fun coding 🙃

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 82%. Comparing base (9d1abd8) to head (f625ecf).
Report is 2 commits behind head on main.

Additional details and impacted files

@@         Coverage Diff         @@
##           main   #234   +/-   ##
===================================
  Coverage    82%    82%           
===================================
  Files        13     13           
  Lines      1044   1045    +1     
===================================
+ Hits        853    854    +1     
  Misses      191    191