chore(sdk): add README (#13975)

Adds README

packages/sdk/README.md

@@ -0,0 +1,191 @@
+# Payload SDK
+
+Package to allow querying Payload REST API in a fully type safe way. Has support for all necessary operations, including auth, type safe `select`, `populate`, `joins` properties and simplified file uploading. Its interface is _very_ similar to the Local API.
+
+```ts
+import { PayloadSDK } from '@payloadcms/sdk'
+import type { Config } from './payload-types'
+
+// Pass your config from generated types as generic
+const sdk = new PayloadSDK<Config>({
+  baseURL: 'https://example.com/api',
+})
+
+// Find operation
+const posts = await sdk.find({
+  collection: 'posts',
+  draft: true,
+  limit: 10,
+  locale: 'en',
+  page: 1,
+  where: { _status: { equals: 'published' } },
+})
+
+// Find by ID operation
+const posts = await sdk.findByID({
+  id,
+  collection: 'posts',
+  draft: true,
+  locale: 'en',
+})
+
+// Auth login operation
+const result = await sdk.login({
+  collection: 'users',
+  data: {
+    email: 'dev@payloadcms.com',
+    password: '12345',
+  },
+})
+
+// Create operation
+const result = await sdk.create({
+  collection: 'posts',
+  data: { text: 'text' },
+})
+
+// Create operation with a file
+// `file` can be either a Blob | File object or a string URL
+const result = await sdk.create({ collection: 'media', file, data: {} })
+
+// Count operation
+const result = await sdk.count({ collection: 'posts', where: { id: { equals: post.id } } })
+
+// Update (by ID) operation
+const result = await sdk.update({
+  collection: 'posts',
+  id: post.id,
+  data: {
+    text: 'updated-text',
+  },
+})
+
+// Update (bulk) operation
+const result = await sdk.update({
+  collection: 'posts',
+  where: {
+    id: {
+      equals: post.id,
+    },
+  },
+  data: { text: 'updated-text-bulk' },
+})
+
+// Delete (by ID) operation
+const result = await sdk.delete({ id: post.id, collection: 'posts' })
+
+// Delete (bulk) operation
+const result = await sdk.delete({ where: { id: { equals: post.id } }, collection: 'posts' })
+
+// Find Global operation
+const result = await sdk.findGlobal({ slug: 'global' })
+
+// Update Global operation
+const result = await sdk.updateGlobal({ slug: 'global', data: { text: 'some-updated-global' } })
+
+// Auth Login operation
+const result = await sdk.login({
+  collection: 'users',
+  data: { email: 'dev@payloadcms.com', password: '123456' },
+})
+
+// Auth Me operation
+const result = await sdk.me(
+  { collection: 'users' },
+  {
+    headers: {
+      Authorization: `JWT  ${user.token}`,
+    },
+  },
+)
+
+// Auth Refresh Token operation
+const result = await sdk.refreshToken(
+  { collection: 'users' },
+  { headers: { Authorization: `JWT ${user.token}` } },
+)
+
+// Auth Forgot Password operation
+const result = await sdk.forgotPassword({
+  collection: 'users',
+  data: { email: user.email },
+})
+
+// Auth Reset Password operation
+const result = await sdk.resetPassword({
+  collection: 'users',
+  data: { password: '1234567', token: resetPasswordToken },
+})
+
+// Find Versions operation
+const result = await sdk.findVersions({
+  collection: 'posts',
+  where: { parent: { equals: post.id } },
+})
+
+// Find Version by ID operation
+const result = await sdk.findVersionByID({ collection: 'posts', id: version.id })
+
+// Restore Version operation
+const result = await sdk.restoreVersion({
+  collection: 'posts',
+  id,
+})
+
+// Find Global Versions operation
+const result = await sdk.findGlobalVersions({
+  slug: 'global',
+})
+
+// Find Global Version by ID operation
+const result = await sdk.findGlobalVersionByID({ id: version.id, slug: 'global' })
+
+// Restore Global Version operation
+const result = await sdk.restoreGlobalVersion({
+  slug: 'global',
+  id,
+})
+```
+
+Every operation has optional 3rd parameter which is used to add additional data to the RequestInit object (like headers):
+
+```ts
+await sdk.me(
+  {
+    collection: 'users',
+  },
+  {
+    // RequestInit object
+    headers: {
+      Authorization: `JWT ${token}`,
+    },
+  },
+)
+```
+
+To query custom endpoints, you can use the `request` method, which is used internally for all other methods:
+
+```ts
+await sdk.request({
+  method: 'POST',
+  path: '/send-data',
+  json: {
+    id: 1,
+  },
+})
+```
+
+Custom `fetch` implementation and `baseInit` for shared `RequestInit` properties:
+
+```ts
+const sdk = new PayloadSDK<Config>({
+  baseInit: { credentials: 'include' },
+  baseURL: 'https://example.com/api',
+  fetch: async (url, init) => {
+    console.log('before req')
+    const response = await fetch(url, init)
+    console.log('after req')
+    return response
+  },
+})
+```