Update README to include Eleven Labs speech setup

[minghinmatthewlam]

Background

The README.md doesn't include steps to setup Eleven Labs speech, but does include steps for memory backend setup, so wanted to keep it consistent and easy to setup.

Changes

Update README.md with steps to setup with Eleven Labs for speak option

Documentation

n/a

Test Plan

n/a

PR Quality Checklist

• My pull request is atomic and focuses on a single change.
• I have thoroughly tested my changes with multiple different prompts.
• I have considered potential risks and mitigations for my changes.
• I have documented my changes clearly and comprehensively.
• I have not snuck in any "extra" small tweaks changes

[codecov]

Codecov Report

Patch and project coverage have no change.

Comparison is base (fc4b5ad) 36.29% compared to head (798d2d6) 36.29%.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #2884   +/-   ##
=======================================
  Coverage   36.29%   36.29%           
=======================================
  Files          60       60           
  Lines        2849     2849           
  Branches      471      471           
=======================================
  Hits         1034     1034           
  Misses       1753     1753           
  Partials       62       62           

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

☔ View full report in Codecov by Sentry.
📢 Do you have feedback about the report comment? Let us know in this issue.