Add exports entry points to package.json

This supports newer versions of Node and specifies different entrypoints
for import and require.

It also makes the public interface of the package explicit.

package.json

@@ -7,10 +7,19 @@
   "es2015": "dist/es/index.js",
   "type": "module",
   "exports": {
-    "types": "dist/types/index.d.ts",
-    "require": "dist/cjs/index.cjs",
-    "default": "dist/es/index.js"
+    ".": {
+      "types": "./dist/types/index.d.ts",
+      "require": "./dist/cjs/index.cjs",
+      "default": "./dist/es/index.js"
+    },
+    "./SearchableMap": {
+      "types": "./dist/types/SearchableMap.d.ts",
+      "require": "./dist/cjs/SearchableMap.cjs",
+      "default": "./dist/es/SearchableMap.js"
+    }
   },
+  "unpkg": "./dist/umd/index.js",
+  "jsdelivr": "./dist/umd/index.js",
   "types": "./dist/types/index.d.ts",
   "author": "Luca Ongaro",
   "homepage": "https://lucaong.github.io/minisearch/",

rollup.config.js

@@ -47,12 +47,13 @@ export default process.env.BENCHMARKS === 'true' ? [benchmarks] : [
   config({ format: 'cjs', input: 'src/index.ts', output: 'cjs', dir: 'cjs', extension: 'cjs', exports: 'default' }),
   config({ format: 'umd', input: 'src/index.ts', output: 'umd', name: 'MiniSearch' }),
 
-  // Type declarations
-  config({ format: 'es', input: 'src/index.ts', output: 'dts', dir: 'types', extension: 'd.ts' }),
-
   // SearchableMap
   config({ format: 'es', input: 'src/SearchableMap/SearchableMap.ts', output: 'es6' }),
   config({ format: 'es', input: 'src/SearchableMap/SearchableMap.ts', output: 'es5m', dir: 'es5m' }),
   config({ format: 'cjs', input: 'src/SearchableMap/SearchableMap.ts', output: 'cjs', dir: 'cjs', extension: 'cjs', exports: 'default' }),
-  config({ format: 'umd', input: 'src/SearchableMap/SearchableMap.ts', output: 'umd', name: 'MiniSearch' })
+  config({ format: 'umd', input: 'src/SearchableMap/SearchableMap.ts', output: 'umd', name: 'MiniSearch' }),
+
+  // Type declarations
+  config({ format: 'es', input: 'src/index.ts', output: 'dts', dir: 'types', extension: 'd.ts' }),
+  config({ format: 'es', input: 'src/SearchableMap/SearchableMap.ts', output: 'dts', dir: 'types', extension: 'd.ts' })
 ]