Fix readme comment example

[craigfurman]

Regex special characters like . must be escaped for the whole comment
string to be treated as one group, otherwise the comment is truncated.

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Ironically, the example I introduced in my last PR (#11) doesn't work! I'll look into PR'ing the golangci-lint docs site too.

[ashanbrown]

Is there any way we can make it so special characters (other than ( and )) don't need to be escaped?

[ashanbrown]

@craigfurman I didn't see an easy answer to my question. I did make a change at #13 so that at least we don't truncate these strings, but I don't see an easy way to recover the original string prior to regexp parsing.

[craigfurman]

I haven't tested #13 yet, but that looks like it would do the trick!

[craigfurman]

I just tried your PR out, I see what you mean now. Off the top of my head (I've not thought long about this), as long as we're parsing the regex it'll be awkward and error-prone to try to reconstruct a string.

If we want the comment to be treated as an opaque string (and not a regex), we might have to double-parse the input, to extract the forbidden regex and the comment as two capture groups, and then compile the regex portion again. IIRC that was the original implementation of #11, but that had some downsides too.

After #13, I think we're in quite a good place now that the comment isn't truncated. Users might be more likely to figure out what's going on, and hopefully escape the special characters. That's also now documented here, and my PR to update https://golangci-lint.run/usage/linters/ was recently merged.