Added a base category system.

package.json

@@ -39,6 +39,8 @@
     "addtags": "babel-node ./scripts/addMissingKeysToTags.js --presets @babel/env",
     "tags2icons": "babel-node ./scripts/migrateTagsToIcons.js --presets @babel/env",
     "icons2tags": "babel-node ./scripts/migrateIconsToTags.js --presets @babel/env",
+    "icons2categories": "babel-node ./scripts/migrateIconsToCategories.js --presets @babel/env",
+    "categories2icons": "babel-node ./scripts/migrateCategoriesToIcons.js --presets @babel/env",
     "generate:changelog": "babel-node ./scripts/generateChangelog.js --presets @babel/env",
     "checkIcons": "babel-node ./scripts/checkIconsAndCategories.js --presets @babel/env"
   },

scripts/migrateCategoriesToIcons.js

@@ -0,0 +1,14 @@
+import path from 'path';
+import icons from '../icons.json';
+import categories from '../categories.json';
+import { mergeArrays, writeFile } from './helpers';
+
+Object.keys(categories).forEach(categoryName => {
+  categories[categoryName].forEach(iconName => {
+    mergeArrays(icons.icons[iconName].categories, [categoryName]);
+  });
+});
+
+const iconsContent = JSON.stringify(icons, null, 2);
+
+writeFile(iconsContent, 'icons.json', path.resolve(__dirname, '..'));

scripts/migrateIconsToCategories.js

@@ -0,0 +1,15 @@
+import path from 'path';
+import icons from '../icons.json';
+import { writeFile } from './helpers';
+
+const newCategories = {};
+Object.keys(icons.icons).forEach(iconName => {
+  icons.icons[iconName].categories.forEach(categoryName => {
+    newCategories[categoryName] = newCategories[categoryName] || [];
+    newCategories[categoryName].push(iconName);
+  });
+});
+
+const categoriesContent = JSON.stringify(newCategories, null, 2);
+
+writeFile(categoriesContent, 'categories.json', path.resolve(__dirname, '..'));