benchmark,doc,lib: capitalize more comments

PR-URL: https://github.com/nodejs/node/pull/26849
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Vse Mozhet Byt <vsemozhetbyt@gmail.com>

lib/buffer.js

@@ -356,7 +356,7 @@ function fromArrayLike(obj) {
 }
 
 function fromArrayBuffer(obj, byteOffset, length) {
-  // convert byteOffset to integer
+  // Convert byteOffset to integer
   if (byteOffset === undefined) {
     byteOffset = 0;
   } else {