[SR-1145] XCTestSuite doc comments describe behavior exclusive to Apple XCTest

[briancroom]

Previous ID	SR-1145
Radar	None
Original Reporter	@briancroom
Type	Bug
Status	Resolved
Resolution	Done

Additional Detail from JIRA

Votes	0
Component/s	XCTest
Labels	Bug, Documentation, StarterBug
Assignee	None
Priority	Medium

md5: 0ed03ce823738ee5c09d488b11993363

Issue Description:

The current doc comments on `XCTestSuite` are copied verbatim from Apple XCTest headers. They talk about methods and behavior that isn't available (at least yet) on our XCTestSuite implementation. We should rewrite this documentation to be more applicable to the way that the class is used in swift-corelibs-xctest.

Especially in need of attention are the APIs merged in this PR, which added many new classes (XCTestRun etc.) with documentation that doesn't make sense in our context.

A little additional context from @modocache: #89 (comment)

[swift-ci]

Comment by Jon Allured (JIRA)

Submitted PR: #100

[briancroom]

I'm going to close this issue, as its core concern was addressed by jonallured (JIRA User) in his PR. There is certainly room for additional documentation improvements (always!), but that can be tracked elsewhere.