Document that .watchmanconfig should be linked

Change-Id: I20c3f0f2bf42c8cd48c975c38ba6be004050a7d6
Signed-off-by: Edwin Kempin <edwin.kempin@sap.com>
diff --git a/.gitignore b/.gitignore
index 43838b0..b4277e3 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,6 @@
 /.buckversion
 /.buckd
+/.watchmanconfig
 /buck-out
 /bucklets
 /target
diff --git a/src/main/resources/Documentation/build.md b/src/main/resources/Documentation/build.md
index 52180d9..f726c6e 100644
--- a/src/main/resources/Documentation/build.md
+++ b/src/main/resources/Documentation/build.md
@@ -30,6 +30,11 @@
   cd @PLUGIN@ && ln -s bucklets/buckversion .buckversion
 ```
 
+Add link to the .watchmanconfig file:
+```
+  cd @PLUGIN@ && ln -s bucklets/watchmanconfig .watchmanconfig
+```
+
 To build the plugin, issue the following command: