added fs tests

guide/src/qs_12.md

@@ -1 +1,41 @@
 # Static file handling
+
+## Individual file
+
+It is possible to serve static files with tail path pattern and `NamedFile`.
+
+```rust
+extern crate actix_web;
+use actix_web::*;
+use std::path::PathBuf;
+
+fn index(req: HttpRequest) -> Result<fs::NamedFile> {
+    let path: PathBuf = req.match_info().query("tail")?;
+    Ok(fs::NamedFile::open(path)?)
+}
+
+fn main() {
+    Application::default("/")
+        .resource(r"/a/{tail:*}", |r| r.get(index))
+        .finish();
+}
+```
+
+## Directory
+
+To serve all files from specific directory `StaticFiles` type could be used. 
+`StaticFiles` could be registered with `Application::route` method.
+
+```rust
+extern crate actix_web;
+
+fn main() {
+    actix_web::Application::default("/")
+        .route("/static", actix_web::fs::StaticFiles::new(".", true))
+        .finish();
+}
+```
+
+First parameter is a base directory. Second parameter is `show_index`, if it set to *true*
+directory listing would be returned for directories, if it is set to *false*
+then *404 Not Found* would be returned instead of directory listing.