Feature: Knowledge Base APIs (#1002)

- Introduce models & migrations for portals, categories, folders and articles
- CRUD API for portals
- CRUD API for categories

Addresses: #714

Co-authored-by: Sojan <sojan@pepalo.com>

spec/models/kbase/article_spec.rb

@@ -0,0 +1,17 @@
+require 'rails_helper'
+
+RSpec.describe Kbase::Article, type: :model do
+  context 'with validations' do
+    it { is_expected.to validate_presence_of(:account_id) }
+    it { is_expected.to validate_presence_of(:category_id) }
+    it { is_expected.to validate_presence_of(:author_id) }
+    it { is_expected.to validate_presence_of(:title) }
+    it { is_expected.to validate_presence_of(:content) }
+  end
+
+  describe 'associations' do
+    it { is_expected.to belong_to(:account) }
+    it { is_expected.to belong_to(:category) }
+    it { is_expected.to belong_to(:author) }
+  end
+end