Broke out all functionality into plugins

packages/@zblog/toolchain/src/start-page-plugin.ts

@@ -0,0 +1,32 @@
+import { IPluginBuilder, Plugin } from "./typings.js";
+import { readFileAsText, writeTextAsFile } from "./toolchain-helpers.js";
+
+type StartPagePluginOptions = {
+  indexTemplatePath: string;
+  contentTemplateTag: string;
+};
+export class StartPagePlugin implements IPluginBuilder {
+  options: StartPagePluginOptions;
+  constructor(options: StartPagePluginOptions) {
+    this.options = options;
+  }
+  build(): Plugin {
+    return (builderContext) => {
+      let htmlTemplate = readFileAsText(this.options.indexTemplatePath);
+      const links = builderContext.menuManifest
+        .map((m) => `<a href='${m.link}'>${m.name}</a>`)
+        .reverse();
+      const unorderedListItems = links.map((l) => `<li>${l}</li>`).join("\r\n");
+      const html = `
+      <ul>
+        ${unorderedListItems}
+      <ul>
+      `;
+      htmlTemplate = htmlTemplate.replace("{{content}}", html);
+      writeTextAsFile(
+        `${builderContext.outputDirectory}/index.html`,
+        htmlTemplate
+      );
+    };
+  }
+}