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>

app/controllers/api/v1/accounts/kbase/portals_controller.rb

@@ -0,0 +1,32 @@
+class Api::V1::Accounts::Kbase::PortalsController < Api::V1::Accounts::Kbase::BaseController
+  before_action :fetch_portal, except: [:index, :create]
+
+  def index
+    @portals = Current.account.kbase_portals
+  end
+
+  def create
+    @portal = Current.account.kbase_portals.create!(portal_params)
+  end
+
+  def update
+    @portal.update!(portal_params)
+  end
+
+  def destroy
+    @portal.destroy
+    head :ok
+  end
+
+  private
+
+  def fetch_portal
+    @portal = current_account.kbase_portals.find(params[:id])
+  end
+
+  def portal_params
+    params.require(:portal).permit(
+      :account_id, :color, :custom_domain, :header_text, :homepage_link, :name, :page_title, :slug
+    )
+  end
+end