Parameters docs with newline char are not generated correctly

[JoshLove-msft]

For parameters that have descriptions containing a newline char, subsequent lines are missing the leading ///:

[nisha-bhatia]

Ideally, we would like to update the EscapeLines method here to take \n into account. Unfortunately, this is proving to be difficult. We cannot use .ToString(). Updating the code as so:

We could have multiple arguments in each \n segment, leading to a recursive solution. We can also have an Object in a FormattableString? We can't call .ToString() on every object because this method might be overloaded.

I believe it's easier to update the WriteLines methods to just print "\" whenever we see a line break, but then we are manipulating the data in multiple places.

@ArcturusZhang