Support CLI description lines when parsing parameters

Hi, I was wondering if it's possible to support skipping cli description lines before parsing parameters?

```zig
const PARAMS = clap.parseParamsComptime(
\\my-package-name - My Package Description [v0.1.0]
\\
\\-o, --opt Optional argument (default: 3)
\\-h, --help Display help
\\ Positional argument
\\
);
```

Start at the parseParamsComptime entry point and trace how the parameter description lines are currently parsed. Use the example in the issue as the acceptance case: description and blank lines before the options should be skipped while the options and positional argument are still recognized.

Written by the indexing model from the issue text.