[Meilisearch v1.31] Allow `skipCreation` when adding/replacing documents

Description

Meilisearch v1.31.0 introduced a new skipCreation parameter to skip document creationg when using:

• Add or replace documents
• Add or update documents

We want to update this SDK to allow passing the skipCreation parameter to the relevant API calls:

• POST /indexes/{index_uid}/documents
• PUT /indexes/{index_uid}/documents

Tasks

• [ ] Update documents API methods to accept a boolean to skip creation
• [ ] Update test cases for the relevant methods
• [ ] Update the examples in .code-samples.meilisearch.yaml under the add_or_replace_documents_1 and add_or_update_documents_1 keys