Add web front-end and fix API issues

node_modules/tree-kill/index.d.ts

@@ -0,0 +1,13 @@
+/**
+ * Kills process identified by `pid` and all its children
+ *
+ * @param pid
+ * @param signal 'SIGTERM' by default
+ * @param callback
+ */
+declare function treeKill(pid: number, callback?: (error?: Error) => void): void;
+declare function treeKill(pid: number, signal?: string | number, callback?: (error?: Error) => void): void;
+
+declare namespace treeKill {}
+
+export = treeKill;