Pull in MDN documentation with attribution.

Collect documentations on CSS properties and compile into
mdn-documentation.js. Certain properties are excluded because of
inaccurency.

- Fix microsoft/vscode#46866
- Fix microsoft/vscode#46423
- Fix microsoft/vscode#27204

README.md

@@ -61,3 +61,8 @@ License
 (MIT License)
 
 Copyright 2016, Microsoft
+
+With the exceptions of,
+
+- `build/mdn-documentation.js`, which is built upon content from [Mozilla Developer Network](https://developer.mozilla.org/en-US/docs/Web)
+and distributed under CC BY-SA 2.5.

build/mdn-data-importer.js

@@ -6,6 +6,15 @@
 const path = require('path')
 const fs = require('fs')
 
+const mdnDocumentations = require('./mdn-documentation')
+
+const mdnExcludedProperties = [
+  '--*', // custom properties
+  'gap', // grid-gap
+  'row-gap', // grid-row-gap
+  'image-resolution', // https://www.w3.org/TR/css-images-4/#propdef-image-resolution
+]
+
 function buildPropertiesWithMDNData(vscProperties) {
   const propertyMap = {}
 
@@ -22,6 +31,10 @@ function buildPropertiesWithMDNData(vscProperties) {
     }
   }
 
+  mdnExcludedProperties.forEach(p => {
+    delete allMDNProperties[p]
+  })
+
   /**
    * 1. Go through VSC properties. For each entry that has a matching entry in MDN, merge both entry.
    */
@@ -45,7 +58,7 @@ function buildPropertiesWithMDNData(vscProperties) {
     if (!propertyMap[pn]) {
       propertyMap[pn] = {
         name: pn,
-        description: '',
+        desc: mdnDocumentations[pn] ? mdnDocumentations[pn] : '',
         restriction: 'none',
         ...extractMDNProperties(allMDNProperties[pn])
       }