chore: more docs

docs/user_guide/index.md

@@ -0,0 +1,32 @@
+---
+id: index
+title: Introduction
+---
+
+Welcome to the Unleash getting started guides. We know that getting to know a new solution might be tedious. Our goal with this documentation is to guide you through the most essential concepts of Unleash. 
+
+One of the most important aspects of the architecture to understand is that feature toggles are evaluated in a client SDKs which runs as part of your application. This makes toggle evaluations super-fast, but of course it compromises a small update-delay when you change your toggle configurations (in terms of seconds and is configurable). 
+
+We recommend that you read about [our unique architecture](https://www.unleash-hosted.com/articles/our-unique-architecture) to understand some of the basics of the architecture.
+
+## Unleash Server
+
+Before you can connect your application to Unleash you need a Unleash server. You have a few options available. 
+
+1. [Unleash Open-source - Self-managed](/docs/deploy/getting_started)
+2. [Unleash Enterprise - Cloud-hosted](https://www.unleash-hosted.com)
+3. [Unleash Enterprise - Self-hosted](https://www.unleash-hosted.com)
+
+
+
+## System Overview
+
+Unleash is comprised of three parts:
+
+- **Unleash API** - The service holding all feature toggles and their configurations. Configurations declare which activation strategies to use and which parameters they should get.
+- **Unleash UI** - The dashboard used to manage feature toggles, define new strategies, look at metrics, etc.
+- **Unleash SDK** - Used by clients to check if a feature is enabled or disabled. The SDK also collects metrics and sends them to the Unleash API. Activation Strategies are also implemented in the SDK. 
+
+![system_overview](https://raw.githubusercontent.com/Unleash/unleash/master/docs/assets/unleash-diagram.png 'System Overview')
+
+To be super fast (*we talk nano-seconds*), the client SDK caches all feature toggles and their current configuration in memory. The activation strategies are also implemented in the SDK. This makes it really fast to check if a toggle is on or off because it is just a simple function operating on local state, without the need to poll data from the database.

website/i18n/en.json

@@ -176,6 +176,9 @@
       "user_guide/discover-unknown-toggles": {
         "title": "user_guide/discover-unknown-toggles"
       },
+      "user_guide/index": {
+        "title": "Introduction"
+      },
       "user_guide/native_apps": {
         "title": "Working with native apps"
       },
@@ -195,8 +198,8 @@
       "Integrations": "Integrations",
       "Contribute": "Contribute",
       "API": "API",
-      "Help": "Help",
-      "Enterprise": "Enterprise"
+      "Enterprise": "Enterprise",
+      "Help": "Help"
     },
     "categories": {
       "Getting started": "Getting started",

website/sidebars.json

@@ -1,6 +1,7 @@
 {
   "documentation": {
     "Getting started": [
+      "user_guide/index",
       "user_guide/connect_sdk",
       "user_guide/client_sdk",
       "user_guide/create_feature_toggle",

website/siteConfig.js

@@ -66,7 +66,7 @@ const siteConfig = {
 
     // For no header links in the top nav bar -> headerLinks: [],
     headerLinks: [
-        { doc: 'user_guide/connect_sdk', label: 'Documentation' },
+        { doc: 'user_guide/index', label: 'Documentation' },
         { doc: 'deploy/getting_started', label: 'Deploy and manage' },
         { doc: 'integrations/integrations', label: 'Integrations' },
         { doc: 'developer_guide', label: 'Contribute' },