Force node to use CJS to get around dependency import errors

Should resolve #256

Both `@mui/icons-material`
(mui/material-ui#35233) and `lodash`
(lodash/lodash#5107) have problems being
imported in a consuming package when using ESM. The workarounds
attempted in #258 almost
seemed to work (didn't break a downstream bundled package using Vite),
but still caused problems for the original example node application
https://codesandbox.io/p/devbox/pensive-volhard-hyhtls, with errors
like:

```
Error: Cannot find module '/path/to/mui-tiptap-in-node/node_modules/@mui/icons-material/esm/FormatColorFill
```

This approach is inspired by what tss-react does
https://github.com/garronej/tss-react/blob/f5351e42e33f35f18415cfc1ffc6b08eb8ce4d25/package.json
(e.g. see here
garronej/tss-react@4699702
and garronej/tss-react#164).

With this change, this code now works in the node context (though
slightly odd):

```
import pkg from "mui-tiptap";
const { FontSize, HeadingWithAnchor, ResizableImage, TableImproved } = pkg;
```

package.json

@@ -22,25 +22,26 @@
     "dist"
   ],
   "type": "commonjs",
-  "types": "./dist/index.d.ts",
-  "main": "dist/index.js",
+  "types": "./dist/cjs/index.d.ts",
+  "main": "dist/cjs/index.js",
   "module": "dist/esm/index.js",
   "exports": {
     ".": {
-      "types": "./dist/index.d.ts",
-      "require": "./dist/index.js",
-      "import": "./dist/esm/index.js"
+      "types": "./dist/cjs/index.d.ts",
+      "module": "./dist/esm/index.js",
+      "default": "./dist/cjs/index.js"
     },
     "./icons": {
-      "types": "./dist/icons/index.d.ts",
-      "require": "./dist/icons/index.js",
-      "import": "./dist/esm/icons/index.js"
-    }
+      "types": "./dist/cjs/icons/index.d.ts",
+      "module": "./dist/esm/icons/index.js",
+      "default": "./dist/cjs/icons/index.js"
+    },
+    "./package.json": "./package.json"
   },
   "typesVersions": {
     "*": {
       "icons": [
-        "./dist/icons/index.d.ts"
+        "./dist/cjs/icons/index.d.ts"
       ],
       "*": [
         "*"

tsconfig.build.json

@@ -1,5 +1,8 @@
 {
   "extends": "./tsconfig.json",
   "include": ["./src"],
-  "exclude": ["./src/demo", "./src/**/__tests__"]
+  "exclude": ["./src/demo", "./src/**/__tests__"],
+  "compilerOptions": {
+    "outDir": "./dist/cjs"
+  }
 }