Using deep data merge (post tag is inherited from posts/posts.json) and updates to use 0.7.0.

.eleventy.js

@@ -5,6 +5,7 @@ const pluginSyntaxHighlight = require("@11ty/eleventy-plugin-syntaxhighlight");
 module.exports = function(eleventyConfig) {
   eleventyConfig.addPlugin(pluginRss);
   eleventyConfig.addPlugin(pluginSyntaxHighlight);
+  eleventyConfig.setDataDeepMerge(true);
 
   eleventyConfig.addLayoutAlias("post", "layouts/post.njk");
 
@@ -12,6 +13,11 @@ module.exports = function(eleventyConfig) {
     return DateTime.fromJSDate(dateObj, {zone: 'utc'}).toFormat("dd LLL yyyy");
   });
 
+  // https://html.spec.whatwg.org/multipage/common-microsyntaxes.html#valid-date-string
+  eleventyConfig.addFilter('htmlDateString', (dateObj) => {
+    return DateTime.fromJSDate(dateObj).toFormat('yyyy-LL-dd');
+  });
+
   // Get the first `n` elements of a collection.
   eleventyConfig.addFilter("head", (array, n) => {
     if( n < 0 ) {
@@ -21,18 +27,6 @@ module.exports = function(eleventyConfig) {
     return array.slice(0, n);
   });
 
-  // https://html.spec.whatwg.org/multipage/common-microsyntaxes.html#valid-date-string
-  eleventyConfig.addFilter('htmlDateString', (dateObj) => {
-    return DateTime.fromJSDate(dateObj).toFormat('yyyy-LL-dd');
-  });
-
-  // only content in the `posts/` directory
-  eleventyConfig.addCollection("posts", function(collection) {
-    return collection.getFilteredByGlob("./posts/*").sort(function(a, b) {
-      return a.date - b.date;
-    });
-  });
-
   eleventyConfig.addCollection("tagList", require("./_11ty/getTagList"));
 
   eleventyConfig.addPassthroughCopy("img");

_11ty/getTagList.js

@@ -1,11 +1,8 @@
 module.exports = function(collection) {
   let tagSet = new Set();
-  collection.getAllSorted().forEach(function(item) {
+  collection.getAll().forEach(function(item) {
     if( "tags" in item.data ) {
       let tags = item.data.tags;
-      if( typeof tags === "string" ) {
-        tags = [tags];
-      }
 
       tags = tags.filter(function(item) {
         switch(item) {

_data/metadata.json

@@ -1,6 +1,7 @@
 {
   "title": "Your Blog Name",
   "url": "https://myurl.com/",
+  "description": "I am writing about my experiences as a naval navel-gazer.",
   "feed": {
     "subtitle": "I am writing about my experiences as a naval navel-gazer.",
     "filename": "feed.xml",

_includes/layouts/base.njk

@@ -4,6 +4,7 @@
     <meta charset="utf-8">
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
     <title>{{ renderData.title or title or metadata.title }}</title>
+    <meta name="Description" content="{{ renderData.description or description or metadata.description }}">
     <link rel="stylesheet" href="{{ '/css/index.css' | url }}">
     <link rel="stylesheet" href="{{ '/css/prism-base16-monokai.dark.css' | url }}">
     <link rel="alternate" href="{{ metadata.feed.path | url }}" type="application/atom+xml" title="{{ metadata.title }}">

_includes/postslist.njk

@@ -4,7 +4,7 @@
     <a href="{{ post.url | url }}" class="postlist-link">{% if post.data.title %}{{ post.data.title }}{% else %}<code>{{ post.url }}</code>{% endif %}</a>
     <time class="postlist-date" datetime="{{ post.date | htmlDateString }}">{{ post.date | readableDate }}</time>
     {% for tag in post.data.tags %}
-      {%- if tag != "post" -%}
+      {%- if tag != "posts" -%}
       {% set tagUrl %}/tags/{{ tag }}/{% endset %}
       <a href="{{ tagUrl | url }}" class="tag">{{ tag }}</a>
       {%- endif -%}

package.json

@@ -22,7 +22,7 @@
   },
   "homepage": "https://github.com/11ty/eleventy-base-blog#readme",
   "devDependencies": {
-    "@11ty/eleventy": "^0.5.4",
+    "@11ty/eleventy": "^0.7.0",
     "@11ty/eleventy-plugin-rss": "^1.0.3",
     "@11ty/eleventy-plugin-syntaxhighlight": "^2.0.0",
     "luxon": "^1.0.0",

posts/firstpost.md

@@ -1,8 +1,8 @@
 ---
 title: This is my first post.
+description: This is a post on My Blog about agile frameworks.
 date: 2018-05-01
 tags:
-  - post
   - another-tag
 layout: layouts/post.njk
 ---

posts/fourthpost.md

@@ -1,5 +1,6 @@
 ---
 title: This is my fourth post.
+description: This is a post on My Blog about touchpoints and circling wagons.
 date: 2018-09-30
 tags: second-tag
 layout: layouts/post.njk

posts/posts.json

@@ -0,0 +1,5 @@
+{
+  "tags": [
+    "posts"
+  ]
+}

posts/secondpost.md

@@ -1,8 +1,8 @@
 ---
 title: This is my second post.
+description: This is a post on My Blog about leveraging agile frameworks.
 date: 2018-07-04
 tags:
-  - post
   - number-2
 layout: layouts/post.njk
 ---

posts/thirdpost.md

@@ -1,8 +1,8 @@
 ---
 title: This is my third post.
+description: This is a post on My Blog about win-win survival strategies.
 date: 2018-08-24
 tags:
-  - post
   - second-tag
 layout: layouts/post.njk
 ---