Deprecate extension

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

Start by reviewing the extension's published title and README notice, then check the existing references to the integrated terminal, related commands, Terminal Here, and the code runner extension. Done means the extension is clearly marked deprecated and the README directs users to each stated alternative.

Written by the indexing model from the issue text.