check-md: verify code example formatting (#7143)

vlib/benchmark/README.md

@@ -1,42 +1,43 @@
 Example usage of this module:
-```
+```v
 import benchmark
+
 mut bmark := benchmark.new_benchmark()
 // by default the benchmark will be verbose, i.e. it will include timing information
 // if you want it to be silent, set bmark.verbose = false
 for {
-   bmark.step() // call this when you want to advance the benchmark.
-                // The timing info in bmark.step_message will be measured starting from the last call to bmark.step
-   ....
-
-   //bmark.fail() // call this if the step failed
-   //bmark.step_message(('failed')
-
-   bmark.ok() // call this when the step succeeded
-   println( bmark.step_message('ok')
+	bmark.step() // call this when you want to advance the benchmark.
+	// The timing info in bmark.step_message will be measured starting from the last call to bmark.step
+	// ....
+	// bmark.fail() // call this if the step failed
+	// bmark.step_message(('failed')
+	bmark.ok() // call this when the step succeeded
+	println(bmark.step_message('ok'))
 }
-bmark.stop() // call when you want to finalize the benchmark
-println( bmark.total_message('remarks about the benchmark') )
+bmark.stop()
+// call when you want to finalize the benchmark
+println(bmark.total_message('remarks about the benchmark'))
 ```
 
 benchmark.start() and b.measure() are convenience methods,
 intended to be used in combination. Their goal is to make
 benchmarking of small snippets of code as *short*, easy to
 write, and then to read and analyze the results, as possible.
+
 Example:
 ```v
 import time
 import benchmark
-mut b := benchmark.start()
 
+mut b := benchmark.start()
 // your code section 1 ...
 time.sleep_ms(1500)
 b.measure('code_1')
-
 // your code section 2 ...
 time.sleep_ms(500)
 b.measure('code_2')
 ```
+
 ... which will produce on stdout something like this:
 ```text
 SPENT 1500.063 ms in code_1