readFileSync、writeFileSyncの例を修正 (#737)

Author: chvmvd

docs/3-web-servers/04-module/_samples/read-file-sync/main.mjs

@@ -1,2 +1,2 @@
 import { readFileSync } from "node:fs";
-console.log(readFileSync("sample.txt", "utf-8"));
+console.log(readFileSync("./sample.txt", "utf-8"));

docs/3-web-servers/04-module/_samples/read-file-sync/sample.txt

@@ -1 +1 @@
-Hello World
+Hello World!

docs/3-web-servers/04-module/_samples/write-file-sync/main.mjs

@@ -1,2 +1,2 @@
 import { writeFileSync } from "node:fs";
-writeFileSync("./sample.txt", "Hello World");
+writeFileSync("./sample.txt", "Hello World!");

docs/3-web-servers/04-module/index.mdx

@@ -92,11 +92,11 @@ Node.js の [`fs` 標準モジュール](https://nodejs.org/api/fs.html) を用
 
 ```javascript title="main.mjs"
 import { readFileSync } from "node:fs";
-console.log(readFileSync("sample.txt", "utf-8"));
+console.log(readFileSync("./sample.txt", "utf-8"));
 ```
 
 ```plain title="sample.txt"
-Hello World
+Hello World!
 ```
 
 <ViewSource
@@ -121,7 +121,7 @@ Hello World
 
 ```javascript title="main.mjs"
 import { writeFileSync } from "node:fs";
-writeFileSync("./sample.txt", "Hello World");
+writeFileSync("./sample.txt", "Hello World!");
 ```
 
 <ViewSource