Document worker publication

Closes #254 (closed)

docs/contents/workers/publication.md

@@ -25,5 +25,5 @@ Since the publication is done during a GitLab CI, no optional arguments are [nee
 
 In the template, a publication to <https://demo.arkindex.org> (slug `demo`) is presented. To publish to another instance, make sure that:
 
-- the authentication credentials are presnet in the secure file,
+- the authentication credentials are present in the secure file,
 - the slug is listed as a potential value for `ARKINDEX_INSTANCE` in the `publish-worker` job configuration.