add with shared for group projects filter (#415)

* Added ```withShared()``` to ```GroupProjectsFilter```
* Cleaned up Javadocs for ```withIncludeSubGroups()```

src/main/java/org/gitlab4j/api/models/GroupProjectsFilter.java

@@ -20,6 +20,7 @@ public class GroupProjectsFilter {
     private Boolean withCustomAttributes;
     private Boolean withIssuesEnabled;
     private Boolean withMergeRequestsEnabled;
+    private Boolean withShared;
     private Boolean includeSubGroups;
 
     /**
@@ -145,9 +146,9 @@ public class GroupProjectsFilter {
     }
 
     /**
-     * Includes projects that are located in sub groups
+     * Include projects that are located in subgroups
      *
-     * @param includeSubGroups if true, projects from sub groups will be included
+     * @param includeSubGroups if true, projects from subgroups will be included
      * @return the reference to this ProjectFilter instance
      */
     public GroupProjectsFilter withIncludeSubGroups(Boolean includeSubGroups) {
@@ -155,6 +156,17 @@ public class GroupProjectsFilter {
         return (this);
     }
 
+    /**
+     * Include projects that are shared with this group
+     *
+     * @param withShared if true, projects that are shared with this group will be included
+     * @return the reference to this ProjectFilter instance
+     */
+    public GroupProjectsFilter withShared(Boolean withShared) {
+        this.withShared = withShared;
+        return (this);
+    }
+
     /**
      * Get the query params specified by this filter.
      *
@@ -173,6 +185,7 @@ public class GroupProjectsFilter {
             .withParam("with_custom_attributes", withCustomAttributes)
             .withParam("with_issues_enabled", withIssuesEnabled)
             .withParam("with_merge_requests_enabled ", withMergeRequestsEnabled)
+            .withParam("with_shared", withShared)
             .withParam("include_subgroups", includeSubGroups)
         );
     }