Extend the overview

doc/index.md

@@ -7,12 +7,38 @@ library to the mix. The final product offers an easy to use Emacs
 configuration for Emacs newcomers and lots of additional power for
 Emacs power users.
 
+!!! Important
+
     Prelude is compatible **ONLY with GNU Emacs 25.1+**. In general you're
-advised to always run Prelude with the latest Emacs - currently
+    advised to always run Prelude with the latest Emacs - currently **26.1**.
-**26.1**.
 
 You can support the development of Prelude via
 [PayPal](https://www.paypal.me/bbatsov),
 [Salt](https://bountysource.com/teams/prelude),
 [Patreon](https://www.patreon.com/bbatsov) and
 [Liberapay](https://liberapay.com/bbatsov/donate).
+
+## Philosophy
+
+Prelude's philosophy is quite simple:
+
+* simple
+* easy to understand and extend
+* stable
+* a foundation for you to build upon, as opposed to some end-user product
+
+This means that it intentionally doesn't pack all the bells and whistles that it could.
+Prelude aims to enhance the classic Emacs experience without deviating a lot from it - e.g.
+it would never enable something like `evil-mode` (vim keybindings) by default and so on.
+
+All the third-party packages that it bundles are carefully vetted and are known to be of
+good quality and to have reliable maintainers. That generally means that Prelude's unlikely
+to immediate adopt some shiny new package, that has established tried and true alternatives.
+
+## Features
+
+* Improved UX, that's still in line with Emacs traditions
+* Sane defaults of baseline Emacs functionality
+* A curated set of 3rd party packages to enhance the base functionality
+* Simple modular architecture
+* Easy customization