Include codemirror libs for svelte

ts/editor/BUILD.bazel

@@ -22,6 +22,8 @@ compile_svelte(
     visibility = ["//visibility:public"],
     deps = [
         "//ts/components",
+        "@npm//@types/codemirror",
+        "@npm//codemirror",
     ],
 )
 

ts/editor/change-timer.ts

@@ -4,12 +4,12 @@
 export class ChangeTimer {
     private value: number | null = null;
 
-    schedule(action: () => void, delay: number) {
+    schedule(action: () => void, delay: number): void {
         this.clear();
         this.value = setTimeout(action, delay);
     }
 
-    clear() {
+    clear(): void {
         if (this.value) {
             clearTimeout(this.value);
             this.value = null;