Add the "Benchmarks" section on the "Performance" page

The commands were taken from this article and adapted to Redox.

src/ch09-10-performance.md

@@ -193,7 +193,7 @@ dd bs=1M count=1024 if=/scheme/zero | md5sum
 dd bs=1M count=1024 if=/scheme/zero of=/scheme/null
 ```
 
-- SSD/HDD read speed benchmark
+- Filesystem read speed benchmark
 
 (Add the `neverball` recipe on your filesystem image, you install it with the `sudo pkg install neverball` command)
 
@@ -201,7 +201,7 @@ dd bs=1M count=1024 if=/scheme/zero of=/scheme/null
 dd bs=1M count=256 if=/usr/games/neverball/neverball of=/scheme/null conv=fdatasync
 ```
 
-- SSD/HDD write speed benchmark
+- Filesystem write speed benchmark
 
 ```sh
 dd bs=1M count=256 if=/scheme/zero of=storage_write_speed_bench.txt conv=fdatasync