Resolve "Updates to the data team page"

Issue

Closes #3962 (closed) and https://gitlab.com/gitlab-data/analytics/issues/956

Solution

This MR:

• adds info on dbt packages
• links to the Snowflake paradigm doc
• fixing the broken link to the SQL style guide
• edits the principles blog
• fixes an error in the SQL Style Guide code example (Commit Link)
• Separates dbt-specific comments to the bottom of the Style Guide