feat(jekyll-engine): implement markdownify for jekyll live editing

`markdownify` uses a different kramdown implementation than jekyll,
so the output is not guaranteed to be identical.

Author: bglw

javascript-modules/engines/jekyll-engine/lib/engine.js

@@ -10,6 +10,7 @@ import jsonify from './plugins/jsonify.js';
 import slugify from './plugins/slugify-plugin.js';
 import unbind from './plugins/unbind.js';
 import loop_context from './plugins/loop_context.js';
+import markdownify from './plugins/markdownify.js';
 import emulateJekyll from './plugins/emulate-jekyll.js';
 import local from './plugins/local.js';
 
@@ -26,7 +27,7 @@ export class Engine {
         this.name = options.name;
         this.files = options.files;
         this.plugins = options.plugins || [];
-        this.plugins.push(jsonify, slugify, unbind, emulateJekyll, local, liquidHighlight, loop_context);
+        this.plugins.push(jsonify, slugify, unbind, emulateJekyll, local, liquidHighlight, loop_context, markdownify);
 
         this.initializeLiquid();
         this.applyLiquidPlugins();

javascript-modules/engines/jekyll-engine/lib/plugins/markdownify.js

@@ -0,0 +1,10 @@
+import kramed from 'kramed';
+
+/**
+ * Implementation of Jekyll's jsonify filter
+ */
+export default function (Liquid) {
+    this.registerFilter('markdownify', (input) => {
+        return kramed(input);
+    });
+}

javascript-modules/engines/jekyll-engine/package.json

@@ -30,6 +30,7 @@
     "@bookshop/helpers": "2.4.1",
     "esbuild": "^0.13.10",
     "js-base64": "^3.6.1",
+    "kramed": "^0.5.6",
     "liquidjs": "9.28.0",
     "slugify": "^1.5.3"
   },

javascript-modules/yarn.lock

@@ -498,6 +498,7 @@ __metadata:
     ava: ^3.15.0
     esbuild: ^0.13.10
     js-base64: ^3.6.1
+    kramed: ^0.5.6
     liquidjs: 9.28.0
     nyc: ^15.1.0
     slugify: ^1.5.3
@@ -5154,6 +5155,15 @@ fsevents@~2.3.2:
   languageName: node
   linkType: hard
 
+"kramed@npm:^0.5.6":
+  version: 0.5.6
+  resolution: "kramed@npm:0.5.6"
+  bin:
+    kramed: ./bin/kramed
+  checksum: 46162eace44bdc28f1b13d6203897b17e26a7f66dd7b16e09fc2107857942e7cf0d383ad6f6307f3fc0f3ab5116fd1949aaa693d0210b87e86a4d4a53471034c
+  languageName: node
+  linkType: hard
+
 "latest-version@npm:^5.1.0":
   version: 5.1.0
   resolution: "latest-version@npm:5.1.0"