chore: regenerate README (#334)

Author: yoshi-automation

.github/readme/synth.metadata/synth.metadata

@@ -4,14 +4,14 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-websecurityscanner.git",
-        "sha": "c518f6e64af74faf0296d90c45d39cb03d7f75e9"
+        "sha": "e3b8c3369ba6b79a03fcd5fda8be7ae3c6c39cb4"
       }
     },
     {
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "6133907dbb3ddab204a17a15d5c53ec0aae9b033"
+        "sha": "a3e990f3545dc8ccd384a75d20ce9cb185ca6a28"
       }
     }
   ]

README.md

@@ -43,10 +43,17 @@ If you are using Maven without BOM, add this to your dependencies:
 
 ```
 
-If you are using Gradle, add this to your dependencies
+If you are using Gradle 5.x or later, add this to your dependencies
+```Groovy
+implementation platform('com.google.cloud:libraries-bom:16.2.0')
+
+compile 'com.google.cloud:google-cloud-websecurityscanner'
+```
+If you are using Gradle without BOM, add this to your dependencies
 ```Groovy
 compile 'com.google.cloud:google-cloud-websecurityscanner:1.0.9'
 ```
+
 If you are using SBT, add this to your dependencies
 ```Scala
 libraryDependencies += "com.google.cloud" % "google-cloud-websecurityscanner" % "1.0.9"