README: add more links/information

Help people learn how to download and contribute to the project.

Change-Id: I4b88b9b3872485ce78c7f6ea50596228afd82843
Reviewed-on: https://go-review.googlesource.com/49870Reviewed-by: Miguel Bernabeu <miguelbernadi@gmail.com>
Reviewed-by: Kevin Burke <kev@inburke.com>

README.md

@@ -25,13 +25,21 @@ localperfdata -addr=:8081 -view_url_base=http://localhost:8080/search?q=upload:
 localperf -addr=:8080 -storage=http://localhost:8081
 ```
 
-The storage system is designed to have a
-[standardized API](https://perfdata.golang.org/), and we
-encourage additional analysis tools to be written against the API. A
-client can be found in the [storage](https://godoc.org/golang.org/x/perf/storage) package.
+The storage system is designed to have a [standardized
+API](https://perfdata.golang.org/), and we encourage additional analysis
+tools to be written against the API. A client can be found in the
+[storage](https://godoc.org/golang.org/x/perf/storage) package.
 
---
+## Download/Install
 
-Contributions to Go are appreciated. See http://golang.org/doc/contribute.html.
+The easiest way to install is to run `go get -u golang.org/x/perf`. You can
+also manually git clone the repository to `$GOPATH/src/golang.org/x/perf`.
 
-* Bugs can be filed at the [Go issue tracker](https://golang.org/issue/new?title=x/perf:+).
+## 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 perf repository is located at
+https://github.com/golang/go/issues. Prefix your issue with "x/perf:" in the
+subject line, so it is easy to find.