Add optional "information" property to custom rules to provide a link to more information.

lib/markdownlint.js

@@ -4,6 +4,7 @@
 
 const fs = require("fs");
 const path = require("path");
+const { URL } = require("url");
 const md = require("markdown-it")({ "html": true });
 const rules = require("./rules");
 const shared = require("./shared");
@@ -41,6 +42,11 @@ function validateRuleList(ruleList) {
         result = newError(property);
       }
     });
+    if (!result && rule.information) {
+      if (Object.getPrototypeOf(rule.information) !== URL.prototype) {
+        result = newError("information");
+      }
+    }
     if (!result) {
       rule.names.forEach(function forName(name) {
         const nameUpper = name.toUpperCase();
@@ -373,6 +379,8 @@ function lintContent(
             errorObject.ruleNames = rule.names;
           }
           errorObject.ruleDescription = rule.description;
+          errorObject.ruleInformation =
+            rule.information ? rule.information.href : null;
           errorObject.errorDetail = error.detail;
           errorObject.errorContext = error.context;
           errorObject.errorRange = error.range;

lib/rules.js

@@ -2,7 +2,12 @@
 
 "use strict";
 
-module.exports = [
+const { URL } = require("url");
+const packageJson = require("../package.json");
+const homepage = packageJson.homepage;
+const version = packageJson.version;
+
+const rules = [
   require("./md001"),
   require("./md002"),
   require("./md003"),
@@ -45,3 +50,9 @@ module.exports = [
   require("./md044"),
   require("./md045")
 ];
+rules.forEach((rule) => {
+  const name = rule.names[0].toLowerCase();
+  rule.information =
+    new URL(`${homepage}/blob/v${version}/doc/Rules.md#${name}`);
+});
+module.exports = rules;