Update README wording

Make linter enabling/disabling via inline comments documentation more
consistent.

Change-Id: If5f26f1c78b72f1dbc295ef25503c8e710b443e3
Reviewed-on: http://gerrit.causes.com/44912
Tested-by: jenkins <jenkins@brigade.com>
Reviewed-by: Shane da Silva <shane.dasilva@brigade.com>