feat(docs): clear up source configs

[hsheth2]

Compare current vs new

Source config presentation:

1. Remove the "collapse" section around configs so that it's more clear that they horizontally scroll.
2. Merge the type into the field name column, and merge the default into the description column. s/o to Brittanie for the design inspiration on this
3. Ensure that the table does not ever need to scroll horizontally.
4. Change the "required if parent set" text to be shown on hover rather than polluting the table.

Source config bug fixes:

1. Fix a bug where basically every field was marked as required.
2. Fix our JSONSchema parsing so that default values of None or False are still shown in the "Default" column.

Other tweaks

• Hide the "questions" section from the sidebar.
• Don't display the "Module snowflake" thing if there's only one source for a given platform.
• Rename the elasticsearch example recipe so that it actually appears in the docs.

Feedback:

• Support collapsing nested fields
• Allow linking directly to a specific config property
• Format the default values so they stand out a bit more

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

[mayurinehate]

LGTM. This is wonderful.