Deprecate extension

[Tyriar]

It looks like people are still installing this extension not knowing about the integrated terminal which can cause a confusing experience. While this extension was useful at one point, I think it's reached the end of its usefulness and is bordering on harmful at this point. I suggest the following actions to improve the situation:

• Mark the extension as deprecated (change extension title to "Terminal (deprecated)" and make use of ":warning:" and "deprecated" in the README notice
• Redirect people to the following:
  • Integrated terminal documentation
  • These commands:
  • The terminal here extension for opening files in the current file https://marketplace.visualstudio.com/items?itemName=Tyriar.vscode-terminal-here
  • Your code runner extension