feat(slack-help-button): added feature flag configurable slack help b…

[Endtry]

Description

In this PR, I added a Slack Help button on the Home Page (top right). The button redirects the user to Datahub's Slack channel on press. There are changes on the server, there's a new feature flag showSlackHelpButton, that defaults to true by default. Setting the flag to false will remove the Slack Button.

Checklist

• The PR conforms to DataHub's Contributing Guideline (particularly Commit Message Format)
• Links to related issues (if applicable)
• Tests for the changes have been added/updated (if applicable)
• Docs related to the changes have been added/updated (if applicable). If a new feature has been added a Usage Guide has been added for the same.
• For any breaking change/potential downtime/deprecation/big changes an entry has been made in Updating DataHub

[xiphl]

Just a suggestion: Personally, I wouldn't tell my datahub users to go to the Datahub Slack, because they'll be asking things from a non technical perspective. May I suggest leaving the URL to be a configurable setting instead?

[maggiehays]

Just a suggestion: Personally, I wouldn't tell my datahub users to go to the Datahub Slack, because they'll be asking things from a non technical perspective. May I suggest leaving the URL to be a configurable setting instead?

@xiphl Thanks for the suggestion! I totally see where you're coming from. We're planning on introducing a set of less-technical-focused Slack channels in the upcoming weeks, so I'm hopeful that folks will have a place to engage with and learn from one another :)

We'll keep it configurable with a feature flag for now & can iterate on it as we get feedback from the community!