docs: add missing backtick in subprocess docs (denoland#8204)

Author: tokiedokie

docs/examples/subprocess.md

@@ -11,7 +11,7 @@
   [stdout](https://doc.deno.land/builtin/stable#Deno.stdout) and
   [stderr](https://doc.deno.land/builtin/stable#Deno.stderr) streams.
 - Use a specific shell by providing its path/name and its string input switch,
-  e.g. `Deno.run({cmd: ["bash", "-c", '"ls -la"']});
+  e.g. `Deno.run({cmd: ["bash", "-c", '"ls -la"']});`
 
 ## Simple example