Merge pull request #4532 from WiXSL/fix-docs-dataprovider-usage

[Doc]: Update dataProvider actions references.

docs/Inputs.md

@@ -934,7 +934,7 @@ import { ReferenceInput, SelectInput } from 'react-admin';
 </Admin>
 ```
 
-**Tip**: Why does `<ReferenceInput>` use the `GET_MANY` verb with a single value `[id]` instead of `GET_ONE` to fetch the record for the current value? Because when there are many `<ReferenceInput>` for the same resource in a form (for instance when inside an `<ArrayInput>`), react-admin *aggregates* the calls to `GET_MANY` into a single one with `[id1, id2, ...)]`. This speeds up the UI and avoids hitting the API too much.
+**Tip**: Why does `<ReferenceInput>` use the `dataProvider.getMany()` method with a single value `[id]` instead of `dataProvider.getOne()` to fetch the record for the current value? Because when there are many `<ReferenceInput>` for the same resource in a form (for instance when inside an `<ArrayInput>`), react-admin *aggregates* the calls to `dataProvider.getMany()` into a single one with `[id1, id2, ...)]`. This speeds up the UI and avoids hitting the API too much.
 
 Set the `allowEmpty` prop when you want to add an empty choice with a value of `null` in the choices list.
 Disabling `allowEmpty` does not mean that the input will be required. If you want to make the input required, you must add a validator as indicated in [Validation Documentation](./CreateEdit.md#validation). Enabling the `allowEmpty` props just adds an empty choice (with `null` value) on top of the options, and makes the value nullable.

docs/List.md

@@ -207,7 +207,7 @@ const PostList = props => (
 )
 ```
 
-In many cases, you'll need more than simple object manipulation. You'll need to *augment* your objects based on relationships. For instance, the export for comments should include the title of the related post - but the export only exposes a `post_id` by default. For that purpose, the exporter receives a `fetchRelatedRecords` function as second parameter. It fetches related records using your `dataProvider` and the `GET_MANY` verb, and returns a promise.
+In many cases, you'll need more than simple object manipulation. You'll need to *augment* your objects based on relationships. For instance, the export for comments should include the title of the related post - but the export only exposes a `post_id` by default. For that purpose, the exporter receives a `fetchRelatedRecords` function as second parameter. It fetches related records using your `dataProvider.getMany()` method, and returns a promise.
 
 Here is an example for a Comments exporter, fetching related Posts:
 
@@ -217,7 +217,7 @@ import { List, downloadCSV } from 'react-admin';
 import jsonExport from 'jsonexport/dist';
 
 const exporter = (records, fetchRelatedRecords) => {
-    // will call dataProvider(GET_MANY, 'posts', { ids: records.map(record => record.post_id) }), ignoring duplicate and empty post_id
+    // will call dataProvider.getMany('posts', { ids: records.map(record => record.post_id) }), ignoring duplicate and empty post_id
     fetchRelatedRecords(records, 'post_id', 'posts').then(posts => {
         const data = records.map(record => ({
                 ...record,