Fix directory path in README for running example

[ashitaprasad]

Currently, in the documentation page typescript/01-tutorials/01-fundamentals/06-browser-agent/README.md under the section 'Running the Example' the code block mentions :

cd typescript/01-tutorials/01-fundamentals/03-browser-agent

It should instead be

cd typescript/01-tutorials/01-fundamentals/06-browser-agent

Also, sending a PR for the fix.