feat(doc): update README with relevant overhead numbers

README.md

@@ -15,7 +15,7 @@ There is an example in `examples/overhead.rs` you can try it with the following
 command :
 
 ```bash
-cargo run --release --example overhead -- --reactivity-us 10 --n-iter 100 --duration-us 1000
+cargo run --release --example overhead -- --reactivity-us 100 --n-iter 1000 --duration-us 10
 ```
 
 The arguments are :
@@ -25,15 +25,9 @@ The arguments are :
 - Reactivity is the targeted duration (in microseconds) between each
   `yield_now().await` inserted by our iterator.
 
-Typical overhead values with a constant amount of work targeted of one seconds
-with no reactivity constraint :
-
-| Overhead | Task duration | N tasks | Reactivity |
-| -------- | ------------- | ------- | ---------- |
-| ~ 1%     | 10 ms         | 100     | infinity   |
-| ~ 15%    | 1 ms          | 1000    | infinity   |
-| ~ 60%    | 100 μs        | 10000   | infinity   |
-| ~ 600%   | 10 μs         | 100000  | infinity   |
+Typical overhead values is between 0 and 2% at max for large number of
+iteration. The bad overhead is about 40% and happens when using few iterations
+(<50) with short duration tasks (< 10 μs).
 
 ## TODO :
 
@@ -45,4 +39,3 @@ with no reactivity constraint :
 - `ge, gt, le, lt, eq, ne` ?
 - `min, max, min_by, max_by, min_by_key, max_by_key` ?
 - `product, sum, reduce` ?
-- Why so much overhead ?