minor README doc fix re. collector.perf.cpus

Signed-off-by: Michael Vorburger <mike@vorburger.ch>

Author: vorburger

README.md

@@ -89,11 +89,11 @@ By default, the perf collector will only collect metrics of the CPUs that
 `node_exporter` is running on (ie
 [`runtime.NumCPU`](https://golang.org/pkg/runtime/#NumCPU). If this is
 insufficient (e.g. if you run `node_exporter` with its CPU affinity set to
-specific CPUs) You can specify a list of alternate CPUs by using the
+specific CPUs), you can specify a list of alternate CPUs by using the
 `--collector.perf.cpus` flag. For example, to collect metrics on CPUs 2-6, you
 would specify: `--collector.perf --collector.perf.cpus=2-6`. The CPU
-configuration is zero indexed and can also take a stride value
-`--collector.perf --collector.perf.cpus=1-10:5`, would collect on CPUs
+configuration is zero indexed and can also take a stride value; e.g.
+`--collector.perf --collector.perf.cpus=1-10:5` would collect on CPUs
 1, 5, and 10.