Update README and docs

Signed-off-by: Heinz N. Gies <heinz@licenser.net>

README.md

@@ -53,3 +53,19 @@ extern crate serial_test;
 for earlier versions.
 
 You can then either add `#[serial]` or `#[serial(some_text)]` to tests as required.
+
+For each test, a timeout can be specified with the `timeout_ms` parameter to the [serial](macro@serial) attribute. Note that
+the timeout is counted from the first invocation of the test, not from the time the previous test was completed. This can
+lead to some unpredictable behavior based on the number of parallel tests run on the system.
+```rust
+#[test]
+#[serial(timeout_ms = 1000)]
+fn test_serial_one() {
+  // Do things
+}
+#[test]
+#[serial(test_name, timeout_ms = 1000)]
+fn test_serial_another() {
+  // Do things
+}
+```

serial_test_derive/src/lib.rs

@@ -33,6 +33,7 @@ use std::ops::Deref;
 /// If you want different subsets of tests to be serialised with each
 /// other, but not depend on other subsets, you can add an argument to [serial](macro@serial), and all calls
 /// with identical arguments will be called in serial. e.g.
+///
 /// ````
 /// #[test]
 /// #[serial(something)]
@@ -61,6 +62,24 @@ use std::ops::Deref;
 /// `test_serial_one` and `test_serial_another` will be executed in serial, as will `test_serial_third` and `test_serial_fourth`
 /// but neither sequence will be blocked by the other
 ///
+/// For each test, a timeout can be specified with the `timeout_ms` parameter to the [serial](macro@serial) attribute. Note that
+/// the timeout is counted from the first invocation of the test, not from the time the previous test was completed. This can
+/// lead to some unpredictable behavior based on the number of parallel tests run on the system.
+///
+/// ````
+/// #[test]
+/// #[serial(timeout_ms = 1000)]
+/// fn test_serial_one() {
+///   // Do things
+/// }
+///
+/// #[test]
+/// #[serial(timeout_ms = 1000)]
+/// fn test_serial_another() {
+///   // Do things
+/// }
+/// ````
+///
 /// Nested serialised tests (i.e. a [serial](macro@serial) tagged test calling another) are supported
 #[proc_macro_attribute]
 #[proc_macro_error]