doc: clean up writing-and-running-benchmarks.md

PR-URL: https://github.com/nodejs/node/pull/61345
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Rafael Gonzaga <rafael.nunu@hotmail.com>
Reviewed-By: Ulises Gascón <ulisesgascongonzalez@gmail.com>

doc/contributing/writing-and-running-benchmarks.md

@@ -43,16 +43,19 @@ By default, `wrk` will be used as the benchmarker. If it is not available,
 `autocannon` will be used in its place. When creating an HTTP benchmark, the
 benchmarker to be used should be specified by providing it as an argument:
 
-`node benchmark/run.js --set benchmarker=autocannon http`
-
-`node benchmark/http/simple.js benchmarker=autocannon`
+```bash
+node benchmark/run.js --set benchmarker=autocannon http
+node benchmark/http/simple.js benchmarker=autocannon
+```
 
 #### HTTPS benchmark requirements
 
 To run the `https` benchmarks, one of `autocannon` or `wrk` benchmarkers must
 be used.
 
-`node benchmark/https/simple.js benchmarker=autocannon`
+```bash
+node benchmark/https/simple.js benchmarker=autocannon
+```
 
 #### HTTP/2 benchmark requirements
 
@@ -60,7 +63,9 @@ To run the `http2` benchmarks, the `h2load` benchmarker must be used. The
 `h2load` tool is a component of the `nghttp2` project and may be installed
 from [nghttp2.org][] or built from source.
 
-`node benchmark/http2/simple.js benchmarker=h2load`
+```bash
+node benchmark/http2/simple.js benchmarker=h2load
+```
 
 ### Benchmark analysis requirements