v8.15.0-alpha.1

What's Changed

• Update generated code and docs to 8.15 by @swallez in bf09d72 and a15f168
• Update dependencies by @swallez in fe436a0, b204d51 and c998c22
• Make id optional for BulkCreateOperation by @dodomorandi in #193
• fix Cat API example by @jeinwag in #212
• Fix documentation examples: missing json format by @eldad in #222
• Extract credentials passed in Url by @russcam in #147
• Derive Clone on Bulk request structs by @jefftt in #202
• Add documentation for msearch by @russcam in #204
• Escape HTML characters in docs by @russcam in #209
• feature: Add multi-node connection pool by @tommilligan in #189
• Add credential using a base64 encoded API key by @swallez in #238
• Allow running on wasm32 targets using fetch() for http requests by @swallez in #200

Full Changelog: v8.5.0-alpha.1...v8.15.0-alpha.1