docs: add BUILD.md, development guide

Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>

2 files changed, 25 insertions, 12 deletions

diff --git a/BUILD.md b/BUILD.md
new file mode 100644
index 00000000..8dc9cc2c
--- /dev/null
+++ b/BUILD.md
@@ -0,0 +1,22 @@
+# Development Guide
+
+## Building the development environment
+
+You need a working [Go environment](https://golang.org/doc/install) (1.11 or newer).
+
+```bash
+$ go get -u github.com/golang/dep/cmd/dep
+$ go get github.com/osrg/gobgp
+$ cd $GOPATH/src/github.com/osrg/gobgp && dep ensure
+```
+
+Now ready to build two binaries, `cmd/gobgp` and `cmd/gobgpd`.
+
+## Changing the gRPC API
+
+If you change the gRPC API, generate `api/gobgp.pb.go` in the following way:
+
+```bash
+$ protoc -I ~/protobuf/src -I ${GOBGP}/api --go_out=plugins=grpc:${GOBGP}/api \
+         ${GOBGP}/api/gobgp.proto ${GOBGP}/api/attribute.proto ${GOBGP}/api/capability.proto
+```
diff --git a/README.md b/README.md
index 7464f650..a8fcbc04 100644
--- a/README.md
+++ b/README.md
@@ -9,20 +9,10 @@ modern environment and implemented in a modern programming language,
 
 ----
 
-## To start using GoBGP
+## Install
 
 Try [a binary release](https://github.com/osrg/gobgp/releases/latest).
 
-## To start developing GoBGP
-
-You need a working [Go environment](https://golang.org/doc/install) (1.11 or newer).
-
-```bash
-$ go get -u github.com/golang/dep/cmd/dep
-$ go get github.com/osrg/gobgp
-$ cd $GOPATH/src/github.com/osrg/gobgp && dep ensure
-```
-
 ## Documentation
 
 ### Using GoBGP
@@ -64,7 +54,8 @@ list](https://lists.sourceforge.net/lists/listinfo/gobgp-devel) for
 questions, discussion, suggestions, etc.
 
 You have code or documentation for GoBGP? Awesome! Send a pull
-request. No CLA, board members, governance, or other mess.
+request. No CLA, board members, governance, or other mess. See [`BUILD.md`](BUILD.md) for info on
+code contributing.
 
 ## Licensing