✨ Add LinkedIn Integration (#942)

* 🚧 node logic, request logic, authentication, logo, descriptions

* 🚧 Posting image, article and text finished.

* 🚧 Posting image, article and text in post finished

* ⚡ Post creation (image, articles, text)

* ⚡ Added post creation by organization, fixed up descriptions, credentials, indentation

* ⚡ Fix issues on LinkedIn-Node

Co-authored-by: Jan Oberhauser <jan.oberhauser@gmail.com>
Co-authored-by: Jan <janober@users.noreply.github.com>

packages/nodes-base/credentials/LinkedInOAuth2Api.credentials.ts

@@ -0,0 +1,55 @@
+import {
+	ICredentialType,
+	NodePropertyTypes,
+} from 'n8n-workflow';
+
+
+export class LinkedInOAuth2Api implements ICredentialType {
+	name = 'linkedInOAuth2Api';
+	extends = [
+		'oAuth2Api',
+	];
+	displayName = 'LinkedIn OAuth2 API';
+	properties = [
+		{
+			displayName: 'Organization Support',
+			name: 'organizationSupport',
+			type: 'boolean' as NodePropertyTypes,
+			default: true,
+			description: 'Request permissions to post as an orgaization.',
+		},
+		{
+			displayName: 'Authorization URL',
+			name: 'authUrl',
+			type: 'hidden' as NodePropertyTypes,
+			default: 'https://www.linkedin.com/oauth/v2/authorization',
+			required: true,
+		},
+		{
+			displayName: 'Access Token URL',
+			name: 'accessTokenUrl',
+			type: 'hidden' as NodePropertyTypes,
+			default: 'https://www.linkedin.com/oauth/v2/accessToken',
+			required: true,
+		},
+		{
+			displayName: 'Scope',
+			name: 'scope',
+			type: 'hidden' as NodePropertyTypes,
+			default: '=r_liteprofile,r_emailaddress,w_member_social{{$parameter["organizationSupport"] === true ? ",w_organization_social":""}}',
+			description: 'Standard scopes for posting on behalf of a user or organization. See <a href="https://docs.microsoft.com/en-us/linkedin/marketing/getting-started#available-permissions"> this resource </a>.'
+		},
+		{
+			displayName: 'Auth URI Query Parameters',
+			name: 'authQueryParameters',
+			type: 'hidden' as NodePropertyTypes,
+			default: '',
+		},
+		{
+			displayName: 'Authentication',
+			name: 'authentication',
+			type: 'hidden' as NodePropertyTypes,
+			default: 'body',
+		},
+	];
+}