refactor: Revamp docs to separate template writers/devs

docs/getting-started.rst

@@ -0,0 +1,37 @@
+Getting Started
+===============
+
+The easiest way to render a template using Stencil is to create a template and
+call render on it providing a context.
+
+.. code-block:: swift
+
+    let template = Template(templateString: "Hello {{ name }}")
+    try template.render(["name": "kyle"])
+
+For more advanced uses, you would normally create an ``Environment`` and call
+the ``renderTemplate`` convinience method.
+
+.. code-block:: swift
+
+    let environment = Environment()
+
+    let context = ["name": "kyle"]
+    try template.renderTemplate(string: "Hello {{ name }}", context: context)
+
+Template Loaders
+----------------
+
+A template loader allows you to load files from disk or elsewhere. Using a
+``FileSystemLoader`` we can easily render a template from disk.
+
+For example, to render a template called ``index.html`` inside the
+``templates/`` directory we can use the following:
+
+.. code-block:: swift
+
+    let fsLoader = FileSystemLoader(paths: ["templates/"])
+    let environment = Environment(loader: fsLoader)
+
+    let context = ["name": "kyle"]
+    try template.renderTemplate(name: "index.html", context: context)