docs: adding base assets documentation

docs/features/assets.md

@@ -2,3 +2,39 @@
 index: 2
 title: "Assets"
 ---
+
+The assets package provides a way to manage web assets in your web application. It receives a folder where your assets are on the disk and returns an http.Handler that serves these files.
+
+This handler is capable of a few things that are useful for web development:
+- Asset fingerprinting (to avoid caching issues)
+- Hot code reloading (when the assets change on disk)
+
+## Usage
+
+The usage of the assets package is centered around the Assets manager instance.
+
+```go
+
+// Assets is the manager for the public assets
+// it allows to watch for changes and reload the assets
+// when changes are made.
+Assets = assets.NewManager(public.Files)
+...
+// Register the assets handler
+// This handler will serve the files from the public folder
+...
+	r.HandleFunc(Assets.HandlerPattern(), Assets.HandlerFn)
+}
+```
+
+## Fingerprinting Helper
+The assets manager provides a PathFor helper that can be used in your templates to use the fingerprinted version of an asset.
+
+```html
+<link rel="stylesheet" href="<%= assets.PathFor("/css/app.css") %>">
+// will output something like
+<link rel="stylesheet" href="/css/app-cafe123ff22112eedd.css">
+```
+
+## Hotcode Reloading
+The assets managers provides a handler function capable of serving the files in the assets filesystem. This handler considers the `GO_ENV` variable to look in for files in disk before looking into the embedded filesystem passed.