Update README.md

Updated docs and examples to match new [ESM standard](https://github.com/smhg/gettext-parser/releases/tag/v8.0.0).

README.md

@@ -9,7 +9,7 @@ Parse and compile gettext *po* and *mo* files with node.js, nothing more, nothin
 
 Include the library:
 
-    var gettextParser = require("gettext-parser");
+    import gettextParser from "gettext-parser";
 
 ### Parse PO files
 
@@ -34,7 +34,8 @@ Method returns gettext-parser specific translation object (see below)
 **Example**
 
 ```javascript
-var input = require('fs').readFileSync('en.po');
+import { readFileSync } from 'node:fs';
+var input = readFileSync('en.po');
 var po = gettextParser.po.parse(input);
 console.log(po.translations['']); // output translations for the default context
 ```
@@ -53,7 +54,8 @@ Where
 **Example**
 
 ```javascript
-var input = require('fs').createReadStream('en.po');
+import { createReadStream } from 'node:fs';
+var input = createReadStream('en.po');
 var po = gettextParser.po.createParseStream();
 input.pipe(po);
 po.on('data', function(data){
@@ -79,11 +81,12 @@ Where
 **Example**
 
 ```javascript
+import { writeFileSync } from 'node:fs';
 var data = {
     ...
 };
 var output = gettextParser.po.compile(data);
-require('fs').writeFileSync('filename.po', output);
+writeFileSync('filename.po', output);
 ```
 
 ### 
@@ -104,7 +107,8 @@ Method returns gettext-parser specific translation object (see below)
 **Example**
 
 ```javascript
-var input = require('fs').readFileSync('en.mo');
+import { readFileSync } from 'node:fs';
+var input = readFileSync('en.mo');
 var mo = gettextParser.mo.parse(input);
 console.log(mo.translations['']); // output translations for the default context
 ```
@@ -122,11 +126,12 @@ Where
 **Example**
 
 ```javascript
+import { writeFileSync } from 'node:fs';
 var data = {
     ...
 };
 var output = gettextParser.mo.compile(data);
-require('fs').writeFileSync('filename.mo', output);
+writeFileSync('filename.mo', output);
 ```
 
 ### Notes