8733: Make docs more precise and add description of known problems

Author: torfsen

clippy_lints/src/methods/mod.rs

@@ -3784,7 +3784,7 @@ declare_clippy_lint! {
     ///
     /// ### Why is this bad?
     ///
-    /// Hard-coding the line endings makes the code less portable. `str.lines` should be used instead.
+    /// Hard-coding the line endings makes the code less compatible. `str.lines` should be used instead.
     ///
     /// ### Example
     /// ```no_run
@@ -3793,6 +3793,11 @@ declare_clippy_lint! {
     /// Use instead:
     /// ```no_run
     /// "some\ntext\nwith\nnewlines\n".lines();
+    ///
+    /// ### Known Problems
+    ///
+    /// This lint cannot detect if the split is intentionally restricted to a single type of newline (`\n` or `\r\n`),
+    /// for example during the parsing of a specific file format in which precisely one newline type is valid.
     /// ```
     #[clippy::version = "1.76.0"]
     pub STR_SPLIT_AT_NEWLINE,