fix(d.ts): TermsAggregation.showTermDocCountError

feat: Implement 'Auto Date Histogram' (sudo-suhas#120)

See https://www.elastic.co/guide/en/elasticsearch/reference/current/search-aggregations-bucket-autodatehistogram-aggregation.html

fix(d.ts): TermsQuery `values` constructor argument type (sudo-suhas#112

)

feat: Support `bool_prefix` type in multi-match query (sudo-suhas#110)

`bool_prefix` was added in Elasticsearch v7.2.

feat: Add method ValuesSourceBase.missingBucket (sudo-suhas#108)

- `ValuesSourceBase` is used in `CompositeAggregation`.
  https://www.elastic.co/guide/en/elasticsearch/reference/current/search-aggregations-bucket-composite-aggregation.html#_missing_bucket.
  This feature was added in Elasticsearch v6.4.
- Add a note for deprecated `ValuesSourceBase.missing` in docs. See
  https://www.elastic.co/guide/en/elasticsearch/reference/6.8/breaking-changes-6.0.html#_literal_missing_literal_is_deprecated_in_the_literal_composite_literal_aggregation

feat: Add support for `track_total_hits` (sudo-suhas#96)

Add method to specify parameter on request body search instance.

Feature was added to elasticsearch in 7.x - 
https://www.elastic.co/guide/en/elasticsearch/reference/7.3/search-request-body.html#request-body-search-track-total-hits

fix(d.ts): Correct GeoShape.coordinates param type

feat: Add method PercolateQuery.documents (sudo-suhas#87)

fix: Make `Sort.field` optional (sudo-suhas#78)

- Annotate `field` parameter as optional in docs and typings.
-  Set `field` on class instance only if it is not nil.

fix(d.ts): Correct param types (sudo-suhas#76)

Add type to `scriptCode` and `scriptId` so they do not have an implicit 
type of any.