doc: add additional build doc

Signed-off-by: Hosung Kim [email protected]

docs/Build.md

@@ -72,3 +72,27 @@ If you are checking out `lwnode` from the GitHub repo (which includes submodules
 ```sh
 $ gbs -c .github/gbs.conf build -A arm7l --include-all --incremental
 ```
+
+#### Build Options
+Use option with `--define '<option_key> <option_value>'`.
+
+For example, If you want to build to static type,
+```sh 
+$ gbs -c .github/gbs.conf build -A arm7l --include-all --incremental --define 'lib_type static'
+```
+
+Options list:
+`lib_type` : shared(default)|static
+
+### 4.3. build lwnode module
+We provide several modules. To build them, use the command below.
+
+```sh
+$ gbs -c .github/gbs.conf build -A arm7l --packaging-dir modules/packages/packaging --include-all --incremental
+```
+
+You can find build result file in `out/modules/tizen`.
+
+Modules lists:
+[device-api](modules/packages/device-api/README.md) 
+[gamain-loop](modules/packages/gamain-loop/README.md)