Make batchs for the indexation

[mdubus]

Split the indexation by making batches of 1000 (by default) documents

[bidoubiwa]

Currently the plugins fetch all data needed to be indexed and send it in one big batch to MeiliSearch

gatsby-plugin-meilisearch/gatsby-node.js

Lines 37 to 38 in b47111a

	// Index data to MeiliSearch
	const { updateId } = await index.addDocuments(transformedData)

We want to avoid, in case the dataset is very large, a payload that is too big for the server hosting MeiliSearch. To do that, the best solution would be to batch the documents in smaller chunks before sending them.

For example if your transformedData has 3500 documents, the plugin should send 3 times a chunk of 1000 documents and once a chunk of 500 documents.

[mdubus]

Closing as this was done with #54