All public interfaces, classes and methods need to be documented

[nickrandolph]

Creating thorough reference docs is an ongoing priority, and we intend to track this work as features become documented. A vital part of this effort is annotating all interfaces, classes and methods that are exposed using inline XML comments. This issue will provide insight around our present coverage pertaining to the entire set of extensions.

The items below that are remaining have not been assigned yet.

Annotated topics

• [x] #1517
• [x] #1519
• [x] #1576
• [x] #1727
• [x] #1531
• [x] #1724
• [x] #1725
• [x] #1585
• [x] #1726

Remaining items

• [ ] #1728
• [ ] #1729
• [ ] #1730

Edited by @lukeblevins: changes to reflect how remaining items are up for grabs