[x/tour] tour: update README to more closely match the blog

The new README for the tour has a similar markdown structure to the
blog, and includes instructions for filing issues and running local
servers.

Change-Id: I8392598d78d4c9b3c0341c38f0a64c52a2aac070
Reviewed-on: https://go-review.googlesource.com/c/148038
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
X-Tour-Commit: df79fa323b803b074d1d58bef988babd261b04bd

tour/README.md

@@ -1,14 +1,41 @@
-A Tour of Go is an introduction to the Go programming language.
+# Go Tour
+
+A Tour of Go is an introduction to the Go programming language. Visit
+https://tour.golang.org to start the tour.
+
+## Download/Install
 
 To install the tour from source, first
 [set up a workspace](https://golang.org/doc/code.html) and then run:
 
 	$ go get golang.org/x/tour
 
-This will place a `tour` binary in your workspace's `bin` directory.
+This will place a `tour` binary in your workspace's `bin` directory, which
+can be run offline.
 
-Unless otherwise noted, the go-tour source files are distributed
-under the BSD-style license found in the LICENSE file.
+## Contributing
 
 Contributions should follow the same procedure as for the Go project:
 https://golang.org/doc/contribute.html
+
+To run the tour server locally:
+
+```sh
+dev_appserver.py app.yaml
+```
+
+and then visit [http://localhost:8080/](http://localhost:8080) in your browser.
+
+## Report Issues / Send Patches
+
+This repository uses Gerrit for code changes. To learn how to submit changes to
+this repository, see https://golang.org/doc/contribute.html.
+
+The main issue tracker for the tour is located at
+https://github.com/golang/go/issues. Prefix your issue with "tour:" in the
+subject line, so it is easy to find.
+
+## License
+
+Unless otherwise noted, the go-tour source files are distributed
+under the BSD-style license found in the LICENSE file.