meta: provide better type declaration for svelte modules

.eslintrc.json

@@ -51,6 +51,7 @@
           "**/*.{spec,mock}.*",
           "src/**/test/*",
           "src/renderer/**/*",
+          "declarations/**/*",
           "templates/**/*",
           "scripts/**/*"
         ]

declarations/svelte.d.ts

@@ -1,7 +1,5 @@
 declare module '*.svelte' {
-  class Component {
-    public constructor(options: { target: HTMLElement });
-  }
-
-  export = Component;
+  import { SvelteComponentTyped } from 'svelte';
+  // noinspection JSUnusedGlobalSymbols -- because it is used
+  export class Component extends SvelteComponentTyped {}
 }