Formatting help text (ends of line)

The [command line wiki](https://github.com/commandlineparser/commandline/wiki) shows what help texts look like:

```
yourapp 2.0.201-alpha
[...]
--filename Input filename.

--help Display this help screen.

--version Display version information.
```
Each argument entry is followed by a **double end of line**. I wondered if there is a simple way to get a formatting with single eol, like this `grep` example:

```
Usage: grep [OPTION]... PATTERN [FILE]...
[...]
-E, --extended-regexp PATTERN is an extended regular expression (ERE)
-F, --fixed-strings PATTERN is a set of newline-separated strings
-G, --basic-regexp PATTERN is a basic regular expression (BRE)

```

If I undestand correctly, I'll have to implement [my own help screen](https://github.com/commandlineparser/commandline/wiki/Generating-Help-and-Usage-information#overriding-the-default-behavior) and use `HelpText.RenderUsageText` or `HelpText.RenderUsageTextAsLines` ?

Start with HelpText.RenderUsageText and HelpText.RenderUsageTextAsLines, the entry points mentioned in the issue, and compare their output with the command line wiki examples. Determine whether help entries can use single end-of-line spacing without replacing the default help screen. Done means the generated help text supports the requested single-EOL formatting and its output is verified against the example.

Written by the indexing model from the issue text.