Kibana version:

Master

Elasticsearch version:

Master

Describe the bug:

In all of the placements where we have a link to the metadata documentation, the button label says "children".

Steps to reproduce:

1. Go to Transaction detail page for any transaction and go to the metadata tab. The same goes for transaction and span detail flyouts

Expected behavior:

The button should show the actual button label "How to add labels and other data".

Technical details

Add brackets around children in:

A test should be added for ElasticDocsLink to avoid this happening again.