Provide Java 18 support

Signed-off-by: Snjezana Peco <snjezana.peco@redhat.com>

Author: snjeza

README.md

@@ -20,7 +20,7 @@ Features
 =========
 ![ screencast ](https://raw.githubusercontent.com/redhat-developer/vscode-java/master/images/vscode-java.0.0.1.gif)
 
-* Supports code from Java 1.5 to Java 17
+* Supports code from Java 1.5 to Java 18
 * Maven pom.xml project support
 * Basic Gradle Java project support (Android not supported)
 * Standalone Java files support
@@ -79,8 +79,8 @@ If you need to compile your projects against a different JDK version, it's recom
     "path": "/path/to/jdk-11",
   },
   {
-    "name": "JavaSE-17",
-    "path": "/path/to/jdk-17",
+    "name": "JavaSE-18",
+    "path": "/path/to/jdk-18",
     "default": true
   },
 ]

package.json

@@ -697,7 +697,8 @@
                   "JavaSE-14",
                   "JavaSE-15",
                   "JavaSE-16",
-                  "JavaSE-17"
+                  "JavaSE-17",
+                  "JavaSE-18"
                 ],
                 "description": "Java Execution Environment name. Must be unique."
               },