doc: some fixes in child_process.md
Checklist
-
documentation is changed or added -
commit message follows commit guidelines
Affected core subsystem(s)
doc, child_process
Description of change
-
assert.equal
=>assert.strictEqual
. -
let
=>const
for the variable that is not reassigned. - Fix indentation and internal spaces in code bits.
- Stringify buffers in code examples to prevent erroneous raw buffer outputs.
- Fix a typo.