Add bing api key to websurfer and fix documentation warnings

[rjambrecic]

Type of change

• Documentation (typos, code examples, or any documentation updates)
• Bug fix (a non-breaking change that resolves an issue)
• New feature (a non-breaking change that adds functionality)
• Breaking change (a fix or feature that would disrupt existing functionality)
• This change requires a documentation update

Checklist

• I have conducted a self-review of my own code
• I have made the necessary changes to the documentation
• My changes do not generate any new warnings
• I have added tests to validate the effectiveness of my fix or the functionality of my new feature
• I have included code examples to illustrate the modifications

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Files with missing lines	Coverage Δ
docs/docs_src/tutorial/giphy/main.py	40.90% <ø> (ø)
docs/docs_src/tutorial/whatsapp/main.py	47.82% <ø> (ø)
.../docs_src/user_guide/runtimes/autogen/websurfer.py	100.00% <ø> (ø)
..._src/user_guide/runtimes/autogen/websurfer_tool.py	100.00% <ø> (ø)
fastagency/adapters/fastapi/base.py	61.37% <ø> (ø)
fastagency/runtimes/autogen/agents/websurfer.py	100.00% <ø> (ø)
fastagency/runtimes/autogen/tools/websurfer.py	79.04% <100.00%> (ø)

... and 1 file with indirect coverage changes