Update known issues.

Author: nicklockwood

README.md

@@ -753,7 +753,7 @@ Known issues
 
 * When using the `extensionAccessControl` rule with the `--extensionacl on-extension` option, if you have public methods defined on an internal type defined in another file, the resultant public extension will no longer compile. The recommended solution is to manually remove the `public` modifier (this won't change the program behavior) or disable the `extensionAccessControl` rule.
 
-* When using the `preferKeyPath` rule, conversion of `compactMap { $0.foo }` to `compactMap(\.foo)` will result in code that fails to compile if `foo` is not an `Optional` property. This is due to a difference in the way that Swift handles type inference for closures vs keyPaths, as discussed [here](https://bugs.swift.org/browse/SR-13347). The recommended workaround is to replace `compactMap()` with `map()` in these cases, which will not change the behavior of the code.
+* When using the `preferKeyPath` rule, conversion of `compactMap { $0.foo }` to `compactMap(\.foo)` or `flatMap { $0.foo }` to `flatMap(\.foo)` will result in code that fails to compile if `foo` is not an `Optional` property. This is due to a difference in the way that Swift handles type inference for closures vs keyPaths, as discussed [here](https://bugs.swift.org/browse/SR-13347). The recommended workaround is to replace `compactMap()` or `flatMap()` with `map()` in these cases, which will not change the behavior of the code.
 
 * When using the `--self remove` option, the `redundantSelf` rule will remove references to `self` in autoclosure arguments, which may change the meaning of the code, or cause it not to compile. To work around this issue, use the `--selfrequired` option to provide a comma-delimited list of methods to be excluded from the rule. The `expect()` function from the popular [Nimble](https://github.com/Quick/Nimble) unit testing framework is already excluded by default. If you are using the `--self insert` option then this is not an issue.