Merge pull request #60 from thefrontside/cl/add-detailed-docs-intro

Add a simple introduction to PlatformScript

Author: taras

www/docs/introduction/index.md

@@ -1,6 +1,45 @@
 ---
 title: Introduction
-description: Docs intro
+description: Introduction to PlatformScript
 ---
 
-PlatformScript is _real_.
+PlatformScript is a declarative, statically typed, secure, and embeddable
+programming language that uses 100% pure YAML as its syntax.
+
+## Features at a Glance.
+
+- Uses lexically scoped **variables** to bind values names to values and
+  reference them later.
+- **Functions** are first class citizens. They can even be bound to variables
+  and passed to other functions for higher order programming.
+- Fluent **templating** allows building strings with _any_ set of PlatformScript
+  expressions, not just simple substitutions.
+- Define new syntactic forms with PlatformScript itself using **macros**.
+- Compose programs with an elegant **module system** for sharing code based on
+  simple URLs.
+- **Native extensions** expose new functionality with any language that can be
+  compiled to WASM
+- Powerful execution model based on **structured concurrency** prevents leaked
+  resources by default.
+
+## Philosophy
+
+PlatformScript is designed to eliminate the bugs, validation errors, and tedium
+of working with YAML by bringing to bear all the rigor and tooling of a modern
+language such as type-checkers, language servers, linters, etc...
+
+It will always use plain YAML without extensions as it syntax, so that
+all PlatformScript programs can be represented as YAML documents, and
+it adopts a policy of "no magic" as in no magic functions, no magic
+variables, and a small, consistent set of evaluation rules.
+
+PlatformScript should always be an excellent choice to replace configuration
+files and special one-off DSLs, especially those that use YAML for their syntax.
+
+## Built with Deno
+
+PlatformScript is built with [Deno][Deno], but more than that, it adopts Deno's
+system of thinking about developer experience; especially as it pertains to
+modules and code sharing.
+
+[Deno]: https://deno.land