Review index settings content to ensure Cloud-related information is up to date

[guimachiavelli]

With the Cloud index setting pages released, we need to review existing index setting content to ensure we have enough information on how to manage index settings in the Cloud.

At the moment, these are the pages we must review:

• reference/api/settings
• learn/getting_started/indexes#index-settings
• learn/relevancy/ranking_rules
• relevancy/custom_ranking_rules
• learn/relevancy/typo_tolerance_settings
• learn/relevancy/distinct_attribute
• learn/relevancy/displayed_searchable_attributes
• learn/relevancy/synonyms