DOC-1095: edit file_line resource, match parameter
DOC-1095: edit file_line resource, match parameter

Was unclear and not accurate; rewrote the parameter, moved file_line from function list to resource section, added missing parameters for this resource.

jbondpdx/puppetlabs-stdlib,HelenCampbell/puppetlabs-stdlib,puppetlabs/puppetlabs-stdlib,DavidS/puppetlabs-stdlib,fuel-infra/puppetlabs-stdlib,yadavnikhil/puppetlabs-stdlib