Code example misses iEnumerable

**Describe the bug**
Displayed C# code doesn't work

**To Reproduce**
Go to the wiki and look at source code C# "Example 1"
https://github.com/commandlineparser/commandline/wiki/HelpText-Configuration

**Additional context**
The the code "Example 1" following code is wrong:
```
static void DisplayHelp(ParserResult result)
```

It should be
```
static void DisplayHelp(ParserResult result,IEnumerable< Error> errs)
```