Add a step to allow our team access to read and view a team's manifest group under 'provisioning a team'

Update link to 'Use user group to control access' in how-to.md

The link checker caught this link as broken, so I did a quick google search to get the updated URL.

INPLATFORM-231

INPLATFORM-115

Move login info to howto

Add content in `concepts` document into two individual document inside best practises - INPLATFORM-154

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