Add VSCode configuration files for C development

- Introduced .vscode/extensions.json to recommend the Clangd extension for improved C code support.
- Added .vscode/settings.json to enable format on save and configure Clang format style for consistent code formatting.
- Updated comments in bitcount.c for clarity on hexadecimal usage.

Author: ohkimur

.vscode/extensions.json

@@ -0,0 +1,3 @@
+{
+  "recommendations": ["llvm-vs-code-extensions.vscode-clangd"]
+}

.vscode/settings.json

@@ -0,0 +1,10 @@
+{
+  "editor.formatOnSave": true,
+  "[c]": {
+    "editor.formatOnSave": true
+  },
+  "C_Cpp.clang_format_style": "file",
+  "C_Cpp.clang_format_fallbackStyle": "LLVM"
+}
+
+

chapter_2/exercise_2_09/bitcount.c

@@ -5,8 +5,8 @@ void printbits(unsigned int x);
 int bitcount(unsigned int x);
 
 int main(void) {
-    // Using hexadecimal instead of binary literals (0b...) for C89/C99 compatibility
-    // 0x1A = 0b011010
+    // Using hexadecimal instead of binary literals (0b...) for C89/C99
+    // compatibility 0x1A = 0b011010
     unsigned int x = 0x1A;
 
     printbits(x);