Update Publishing documentatation

This fixes the outdated reference to the master branch, fixes a typo and
makes it clear that changes are sent to Publishing API rather than
Content Store.

docs/tasks/publishing.md

@@ -1,5 +1,5 @@
 ### Publishing
 
-Changes to smart answer pages need to be sent to be sent to the `content store` for them to appear on GOV.UK.
+Changes to smart answer pages need to be sent to the Publishing API for them to appear on GOV.UK.
 
-The [rake task `publishing_api:sync_all`](https://github.com/alphagov/smart-answers/blob/master/lib/tasks/publishing_api.rake) needs to be run once you have deployed your changes in each environment and can be done in [Jenkins](https://deploy.integration.publishing.service.gov.uk/job/run-rake-task/parambuild/?TARGET_APPLICATION=smartanswers&MACHINE_CLASS=calculators_frontend&RAKE_TASK=publishing_api:sync_all).
+The [rake task `publishing_api:sync_all`](../../lib/tasks/publishing_api.rake) needs to be run once you have deployed your changes in each environment and can be done in [Jenkins](https://deploy.integration.publishing.service.gov.uk/job/run-rake-task/parambuild/?TARGET_APPLICATION=smartanswers&MACHINE_CLASS=calculators_frontend&RAKE_TASK=publishing_api:sync_all).