feat(docs): add explanation for notion-client

packages/notion-client/readme.md

@@ -36,6 +36,123 @@ const collectionData = await api.getCollectionData(
 )
 ```
 
+### Fetch a database's content
+
+You can pass a database ID to the `getPage` method. The response is an object which contains several important properties:
+
+- `block`
+- `collection`
+- `collection_view`
+
+The value of the `block` property maps the id of each block object present in the database to its corresponding properties like type, parent id, created time, last edited by, and more. 
+
+```
+{
+  block: {
+    'cc368b47-772a-4a1a-a36e-1f52c507d20d': { role: 'reader', value: [Object] },
+    '97dbe6d5-aea3-4e03-b571-91810cf975d4': { role: 'reader', value: [Object] },
+    '08d5ba1e-03d2-4d4a-add7-a414f297ff8a': { role: 'reader', value: [Object] },
+    '7aad4627-c4af-4314-960e-1465e76cc6bd': { role: 'reader', value: [Object] },
+    '7be73360-19b9-4b77-a518-70acd610d492': { role: 'reader', value: [Object] },
+    'af961803-cd0c-470e-bd27-1d025baa2f95': { role: 'reader', value: [Object] },
+    // ...
+  }
+}
+```
+
+The map of blocks is arranged as followed:
+
+- The first id is of the collection view
+- The second is of the parent page that contains the database in question
+- The next ids are of all the children pages inside the database
+- After that comes all the children blocks of each page.
+
+
+Please note that a block object can take many types: header, text, list, media, and almost any block supported by Notion. It can also be *a page* or a *collection view*.
+
+Example of a block object of type `text`:
+
+```
+{
+  role: 'reader',
+  value: {
+    id: '0377e1a4-dc3d-4daf-99dd-f54f986d932e',
+    version: 1,
+    type: 'text',
+    properties: { title: [Array] },
+    format: { copied_from_pointer: [Object] },
+    created_time: 1655961814278,
+    last_edited_time: 1655961814278,
+    parent_id: '08d5ba1e-03d2-4d4a-add7-a414f297ff8a',
+    parent_table: 'block',
+    alive: true,
+    copied_from: '526d2008-0d0b-46f8-9de1-7411a85bff7b',
+    created_by_table: 'notion_user',
+    created_by_id: '55b29a2b-a8fe-4a11-9f9d-ada341bd922b',
+    last_edited_by_table: 'notion_user',
+    last_edited_by_id: '55b29a2b-a8fe-4a11-9f9d-ada341bd922b',
+    space_id: '6b70425f-211e-4318-80c6-5d093df8f7eb'
+  }
+}
+```
+
+Example of a block object of type `page`:
+
+```
+{
+  role: 'reader',
+  value: {
+    id: 'af961803-cd0c-470e-bd27-1d025baa2f95',
+    version: 31,
+    type: 'page',
+    properties: { '==~K': [Array], 'BN]P': [Array], title: [Array] },
+    content: [
+      '8cbf7053-da37-4d69-8cde-89343baf3623',
+      '0fc1712e-852c-4307-b72b-094dadaa86ba'
+    ],
+    created_time: 1655962200000,
+    last_edited_time: 1655979420000,
+    parent_id: '175482e5-870d-4da8-980c-ead469427316',
+    parent_table: 'collection',
+    alive: true,
+    created_by_table: 'notion_user',
+    created_by_id: '55b29a2b-a8fe-4a11-9f9d-ada341bd922b',
+    last_edited_by_table: 'notion_user',
+    last_edited_by_id: '55b29a2b-a8fe-4a11-9f9d-ada341bd922b',
+    space_id: '6b70425f-211e-4318-80c6-5d093df8f7eb'
+  }
+}
+```
+
+Example of a block object of type `collection_view`:
+```
+{
+  role: 'reader',
+  value: {
+    id: 'cc368b47-772a-4a1a-a36e-1f52c507d20d',
+    version: 5,
+    type: 'collection_view',
+    view_ids: [
+      '028f6968-2a6c-46da-bf43-cb44e6d91765',
+      '77f32047-52dd-422e-93fa-813438087e57'
+    ],
+    collection_id: '175482e5-870d-4da8-980c-ead469427316',
+    format: { collection_pointer: [Object], copied_from_pointer: [Object] },
+    created_time: 1655961814276,
+    last_edited_time: 1656075900000,
+    parent_id: '97dbe6d5-aea3-4e03-b571-91810cf975d4',
+    parent_table: 'block',
+    alive: true,
+    copied_from: '3e3073e9-7aee-481c-b831-765e112ec7b5',
+    created_by_table: 'notion_user',
+    created_by_id: '55b29a2b-a8fe-4a11-9f9d-ada341bd922b',
+    last_edited_by_table: 'notion_user',
+    last_edited_by_id: '55b29a2b-a8fe-4a11-9f9d-ada341bd922b',
+    space_id: '6b70425f-211e-4318-80c6-5d093df8f7eb'
+  }
+}
+```
+
 ## Docs
 
 See the [full docs](https://github.com/NotionX/react-notion-x).