text: Title: Dead Link on "Using the Web API" page
  Body: Hello!
  
  I want reading the documentation on using the Web API from the Bolt Python library and found there is a dead link on the page. 
  
  The source of the link is https://slack.dev/bolt-python/concepts/web-api/ and the dead link is in the first sentence for the link for "WebClient": https://slack.dev/python-slack-sdk/basic_usage.html
  
  It's not obvious to me what the correct link is, so I am sharing here in hopes the team knows! 
  
  Thanks in advance!
  
  ### The page URLs
  
  * https://slack.dev/bolt-python/concepts/web-api/ 
  
  ## Requirements
  
  Please read the [Contributing guidelines](https://github.com/slackapi/bolt-python/blob/main/.github/contributing.md) and [Code of Conduct](https://slackhq.github.io/code-of-conduct) before creating this issue or pull request. By submitting, you are agreeing to those rules.
  